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U.S. Silica

slca · NYSE Energy
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FY2022 Annual Report · U.S. Silica
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UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

FORM 10-K

☑ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

For the Fiscal Year Ended December 31, 2022

OR

TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF
1934

☐

Commission file number 001-35416

U.S. Silica Holdings, Inc.

(Exact name of registrant as specified in its charter)

Delaware
(State or other jurisdiction of
Incorporation or Organization)

26-3718801
(I.R.S. Employer
Identification No.)

24275 Katy Freeway, Suite 600
Katy, Texas 77494
(Address of Principal Executive Offices) (Zip Code)

(281) 258-2170
(Registrant’s telephone number, including area code)

Securities registered pursuant to Section 12(b) of the Securities Act:

Title of each class:
Common Stock, par value $0.01 per share

Trading Symbol:
SLCA

Name of each exchange on which registered:
New York Stock Exchange

Securities registered pursuant to Section 12(g) of the Securities Act: None

Indicate by a check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act.    Yes  ☑    No  ☐

Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15 (d) of the Act.    Yes  ☐    No  ☑

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding
12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past
90 days.    Yes  ☑    No  ☐

Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§232.405
of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit such files).    Yes  ☑    No  ☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth
company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and "emerging growth company" in Rule 12b-2 of the Exchange Act.

Large accelerated filer

Non-accelerated filer

☑

☐

   Accelerated filer

Smaller reporting company

Emerging growth company

  ☐

  ☐

☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial
accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Indicate by check mark whether the registrant has filed a report on and attestation to its management's assessment of the effectiveness of its internal control over financial
reporting under Section 404(b) of the Sarbanes-Oxley Act (15 U.S.C. 7262(b)) by the registered public accounting firm that prepared or issued its audit report. ☑

If securities are registered pursuant to Section 12(b) of the Act, indicate by check mark whether financial statements of the registrant included in the filing reflect the correction of
an error to previously issued financial statements. ☐

 
 
 
 
 
 
 
 
 
 
 
 
 
  
Indicate by check mark whether any of those error corrections are restatements that required a recovery analysis of incentive-based compensation received by any of the
registrant's executive officers during the relevant period pursuant to §240.10D-1(b). ☐

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Act).    Yes  ☐    No  ☑

The aggregate market value of the outstanding common stock held by non-affiliates of the registrant as of June 30, 2022, the last business day of the registrant’s most recently
completed second fiscal quarter, was $811,859,083 based on the closing price of $11.42 per share, as reported on the New York Stock Exchange, on such date.

As of February 17, 2023, 76,120,988 shares of common stock, par value $0.01 per share, of the registrant were outstanding.

DOCUMENTS INCORPORATED BY REFERENCE
Certain sections of the Proxy Statement for the 2023 Annual Meeting of Shareholders for U.S. Silica Holdings, Inc. (the “2023 Proxy Statement”) are incorporated by reference
in Part III of this Annual Report on Form 10-K where indicated.

 
 
U.S. Silica Holdings, Inc.
FORM 10-K
For the Fiscal Year Ended December 31, 2022

TABLE OF CONTENTS

PART I

Item 1.
Item 1A.
Item 1B.
Item 2.
Item 3.
Item 4.

Business
Risk Factors
Unresolved Staff Comments
Properties
Legal Proceedings
Mine Safety Disclosures

PART II

Item 5.
Item 6.
Item 7.
Item 7A.
Item 8.
Item 9.
Item 9A.
Item 9B.
Item 9C.

PART III

Item 10.
Item 11.
Item 12.
Item 13.
Item 14.

PART IV

Market for Registrant's Common Equity, Related Stock Holder Matters and Issuer Purchases of Equity Securities
[Reserved]
Management’s Discussion and Analysis of Financial Condition and Results of Operations
Quantitative and Qualitative Disclosures About Market Risk
Financial Statements and Supplementary Data
Changes in and Disagreements with Accountants on Accounting and Financial Disclosure
Controls and Procedures
Other Information
Disclosure Regarding Foreign Jurisdictions That Prevent Inspections

Directors, Executive Officers and Corporate Governance
Executive Compensation
Security Ownership of Certain Beneficial Owners and Management and Related Stockholder Matters
Certain Relationships and Related Transactions, and Director Independence
Principal Accounting Fees and Services

Item 15.
Item 16.

Exhibits and Financial Statement Schedules
Form 10-K Summary

Signatures

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Forward Looking Statements

    This Annual Report on Form 10-K contains forward-looking statements within the meaning of Section 21E of the Securities Exchange Act of
1934, as amended (the “Exchange Act”) and Section 27A of the Securities Act of 1933, as amended. All statements other than statements of
historical fact included in this Annual Report on Form 10-K are forward-looking statements. Forward-looking statements give our current
expectations and projections relating to our financial condition, results of operations, plans, objectives, future performance and business. These
statements may include words such as “anticipate,” “estimate,” “expect,” “project,” “plan,” “intend,” “believe,” “may,” “will,” “should,”
“could,” “can have,” “likely” and other words and terms of similar meaning.

For example, all statements we make relating to our estimated and projected costs and cost reduction programs; reserve and finished
products estimates; demand for our products; the strategies of our customers; anticipated expenditures, cash flows, growth rates and financial
results; our plans and objectives for future operations, growth or initiatives; strategies and their anticipated effect on our performance and
liquidity; and the expected outcome or impact of pending or threatened litigation are forward-looking statements.

All forward-looking statements are subject to risks and uncertainties that may cause actual results to differ materially from those that we

expect. These risks and uncertainties include, but are not limited to, those described in Part I, "Item 1A. Risk Factors" and elsewhere in this
Annual Report on Form 10-K and those described from time to time in our future reports filed with the Securities and Exchange Commission (the
"SEC").

We derive many of our forward-looking statements from our operating budgets and forecasts, which are based on many detailed

assumptions. While we believe that our assumptions are reasonable, it is impossible for us to anticipate all factors that could affect our actual
results. As a result, forward-looking statements are not guarantees of future performance, and you should not place undue reliance on any
forward-looking statements we make.

If one or more of the risks described above or other risks or uncertainties materialize (or the consequences of any such development
changes), or should our underlying assumptions prove incorrect, actual outcomes may vary materially from those reflected in our forward-
looking statements. The forward-looking statements included in this Annual Report on Form 10-K are made only as of the date hereof. We
disclaim any intention or obligation to update publicly or revise such statements, whether as a result of new information, future events or
otherwise. All written and oral forward-looking statements attributable to us, or persons acting on our behalf, are expressly qualified in their
entirety by these cautionary statements as well as other cautionary statements that are made from time to time in our other filings with the SEC,
and our other public communications.

PART I

ITEM 1.

BUSINESS

    Unless we state otherwise, or the context otherwise requires, the terms “we,” “us,” “our,” “U.S. Silica,” “the Company,” “our business,” and “our
company” refer to U.S. Silica Holdings, Inc. and its consolidated subsidiaries as a combined entity.

Our Company

Business Overview

    We are a global performance materials company and a leading producer of commercial silica used in the oil and gas industry and in a wide range of industrial
applications. In addition, through our subsidiary EP Minerals, LLC ("EPM") we are an industry leader in the production of industrial minerals, including
diatomaceous earth, clay (calcium bentonite and calcium montmorillonite) and perlite.

    During our 123-year history, we have developed core competencies in mining, processing, logistics and materials science that enable us to produce and cost-
effectively deliver over 600 diversified product types to customers across our end markets. As of December 31, 2022, we had 27 operating mines and
processing facilities and two additional exploration stage properties across the United States. We control 468 million tons of reserves of commercial silica,
which can be processed to

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make 182 million tons of finished products that meet American Petroleum Institute ("API") frac sand specifications, and 82 million tons of reserves of
diatomaceous earth, perlite, and clays.

    Our operations are organized into two reportable segments based on end markets served and the manner in which we analyze our operating and financial
performance: (1) Oil & Gas Proppants and (2) Industrial & Specialty Products. We believe our segments are complementary because our ability to sell to a wide
range of customers across end markets in these segments allows us to maximize recovery rates in our mining operations and optimize our asset utilization.

Our Business Strategy and Strengths

We attribute our success to the following strengths:

•

Large-scale producer with a diverse and high-quality reserve base. We believe our large-scale production, logistics capabilities and long reserve
life make us a preferred supplier to our customers. Our consistent, reliable supply of reserves gives our customers the security to customize their
production processes around our products. Furthermore, our relatively large scale and wide product portfolio provide us earnings diversification and
the ability to reach broader market segments.

• Geographically advantaged footprint with intrinsic transportation advantages. We believe the strategic location of our facilities and our logistics

capabilities contribute to our customer retention rates and our ability to reach broader market segments. We continue to strategically position our
supply chain in order to deliver sand according to our customers' needs, whether at a plant, a transload, or the wellhead. In our Oil & Gas Proppants
segment, our network of frac sand production facilities with access to barge and Class I rail, either onsite or by truck, combined with the strategic
locations of our transloads, enable us to serve every major U.S. shale basin. Additionally, our SandBox Logistics service ("SandBox") extends our
delivery capability directly to our customers' wellhead locations and provides a lower cost logistics solution. We believe we are one of the few frac
sand producers capable of cost-effectively delivering API grade frac sand to most of the major U.S. shale basins by on-site rail.

Additionally, due to the high weight-to-value ratio of many silica products in our Industrial & Specialty Products segment, the proximity of our
facilities to our customers’ facilities often results in us being their sole supplier. This advantage has enabled us to enjoy strong customer retention in
this segment, with our top five Industrial & Specialty Products segment customers purchasing from us for an average of over 50 years.

Diatomaceous earth, clay, and perlite facilities are located near major highways and export corridors to optimize the cost of operations and shipment.
Products can be shipped via bulk truck, rail or packaged. We utilize experienced in-house international logistics operations using a broad base of
partners to enable efficient and cost-effective exports to approximately 100 countries.

•

Low-cost operating structure. We focus on building and operating facilities with low delivered costs to enable us to better manage market
downturns. We believe the combination of the following factors contributes to our goal of having a low-cost structure and high margins:

•

•

•

•

•

•

our ownership of the vast majority of our reserves, resulting in mineral royalty expense that was approximately 0.5% of our sales in 2022;

the optimal positioning of our mines and their respective processing plants, enabling cost-efficient and highly automated production processes;

the active management of our product mix at each of our plants as we seek to maximize our profit margins which requires us to use our
expertise in balancing key variables such as mine geology, processing capacity, transportation availability, customer requirements, and pricing;

our integrated logistics management expertise and geographically advantaged facility network, which enables us to reliably ship products by the
most cost-effective method available, whether domestic or overseas; we transport products by truck, rail or barge to meet the needs of our
customers, including at in-basin transload locations and directly at wellhead locations via our SandBox operations;

our large customer base across numerous end markets, which allows us to maximize our mining recovery rate and asset utilization; and

our large overall and plant-level operating scale.

•

Focus on safety and positive relationships with the communities in which we operate. We focus on the safety of our employees and maintain safe
and responsible operations. We also believe we are known in the communities in which we operate as a preferred employer and a responsible
corporate citizen, which generally serves us well in hiring new employees and securing difficult to obtain permits for expansions and new facilities.

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•

•

•

Strong reputation with our customers. We believe we have built a strong reputation during our 123-year operating history. We have a long track
record of timely delivery of our products according to customer specifications, which we believe contributes to a reputation for dependability. We
also have an extensive network of technical resources, including materials science and petroleum engineering expertise, which enables us to
collaborate with our customers to develop products to improve the performance of their existing applications.

Commitment to innovation. Our research and development teams work to enhance our existing products and develop new, patentable products. We
expect this will increase our presence and market share in certain specialty products end markets and allow us to enter new markets. We manage a
robust pipeline of new products in various stages of development.

Experienced management team. The members of our senior management team bring significant experience to the dynamic environment in which
we operate. Their expertise covers a range of disciplines, including industry-specific operating and technical knowledge. We believe we have
assembled a flexible, creative and responsive team that can quickly adapt to changing market conditions.

• Maintain financial strength and flexibility. We intend to maintain financial strength and flexibility to enable us to better manage through industry

downturns and pursue acquisitions and new growth opportunities as they arise. In connection with the EPM acquisition, on May 1, 2018, we entered
into a Third Amended and Restated Credit Agreement (the "Credit Agreement") with BNP Paribas, as administrative agent, and the lenders named
therein. The Credit Agreement increased our then existing senior debt by establishing a new $1.380 billion senior secured credit facility, consisting
of a $1.280 billion term loan (the “Term Loan”) and a $100 million revolving credit facility (the “Revolver”) (collectively the "Credit Facility") that
may also be used for swingline loans or letters of credit, and we may elect to increase the term loan in accordance with the terms of the Credit
Agreement. For more information on the Credit Agreement see Note K - Debt to our Consolidated Financial Statements in Part II, Item 8 of this
Annual Report on Form 10-K. As of December 31, 2022, we had $280.8 million of cash on hand and $78.5 million of availability under the
Revolver.

Our Products and Services

In order to serve a broad range of end markets, we produce and sell a variety of commercial silica, diatomaceous earth, clay and perlite products. We also

offer services including transportation, equipment rental and contract labor.

Whole Grain Silica Products—We sell whole grain commercial silica products in a range of shapes, sizes and purity levels. We sell whole grain silica that

has a round shape and high crush strength to be used as frac sand in connection with oil and natural gas recovery. We also sell whole grain silica products in a
range of size distributions, grain shapes and chemical purity levels to our customers involved in the manufacturing of glass products, including a low-iron
whole grain product sold to manufacturers of architectural and solar glass applications. In addition, we sell several grades of whole grain round silica to the
foundry industry and provide whole grain commercial silica to the building products industry.

Performance Material Products—We sell engineered performance materials made from diatomaceous earth (DE), clay and perlite. DE is used in filtration

for foods and beverages, pharmaceuticals and swimming pools. DE is also used as a functional additive for paint and coatings, plastics and rubber, and
agriculture. Perlite (hydrated volcanic glass) is used mainly for filtration. Calcium bentonite clay is used for bleaching, catalysis and adsorption in edible oil
processing, aromatics purification, and industrial and chemical applications.

Services—We offer services through the provision of transportation, equipment rental and contract labor services, primarily through SandBox, to

companies in the oil and gas industry.

Additionally, we sell ground silica and industrial minerals products for use in a wide variety of products.

Our Industry and Primary End Markets

The commercial silica industry consists of businesses that are involved in the mining, processing and distribution of commercial silica. Commercial silica,

also referred to as “silica,” “industrial sand and gravel,” “sand,” “silica sand” and “quartz sand,” is a term applied to sands and gravels containing a high
percentage of silica (silicon dioxide, SiO ) in the form of quartz. Commercial silica deposits occur throughout the United States, but mines and processing
facilities are typically located near end markets and in areas with access to transportation infrastructure. Other factors affecting the feasibility of commercial
silica production include deposit composition, product quality specifications, land-use and environmental regulation, including permitting requirements, access
to electricity, natural gas and water and a producer’s expertise and know-how. New entrants face hurdles to establish their operations, including the capital
investment required to develop a mine and build a plant, a lack of

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industry-specific mining knowledge and experience, the difficulty of obtaining operating permits, and the difficulty of assembling a diverse portfolio of
customers to optimize operations.

The special properties of commercial silica such as chemistry, purity, grain size, color, inertness, hardness and resistance to high temperatures make it
critical to a variety of industries. Commercial silica is a key input in the well completion process, specifically, in the hydraulic fracturing techniques used in
unconventional oil and natural gas wells. In the Industrial and Specialty Products end markets, stringent quality requirements must be met when commercial
silica is used as an ingredient to produce thousands of everyday products, including glass, building and foundry products and metal castings, as well as certain
specialty applications such as high-performance glass, specialty coatings, polymer additives and geothermal energy systems (such as solar panels). Due to the
unique properties of commercial silica, we believe it is an economically irreplaceable raw material in a wide range of industrial applications.

EPM's DE, perlite, montmorillonite clay and bentonite clay products are sold globally, where they are used in hundreds of applications. High quality DE

possesses superior characteristics for filtration, functional additives, absorbents and adsorbents. The largest industries for these products include food and
beverage, wine, beer, paint and coatings, biofuel, pharmaceuticals, chemical, oil and gas, plastics and rubber, automotive and agriculture. The perlite (hydrated
volcanic glass) is used for filtration, lightweight construction, horticulture, and insulation. The calcium bentonite clay from Mississippi and calcium
montmorillonite clay from Tennessee are thermally processed to produce powder and granular products for bleaching clays, absorbents, catalysis, and
adsorbents.

Commercial silica deposits are formed from a variety of sedimentary processes and have distinct characteristics that range from hard sandstone rock to

loose, unconsolidated dune sands. While the specific extraction method utilized depends primarily on the deposit composition, most silica is mined using
conventional open-pit bench extraction methods and begins after clearing the deposit of any overlaying soil and organic matter. The silica deposit composition
and chemical purity also dictate the processing methods and equipment utilized.

We conduct only surface mining operations and do not operate any underground mines, although we do lease underground reserves at our Festus,
Missouri operation, which are being mined underground by a contractor. Mining methods at our facilities include conventional hard rock mining, hydraulic
mining, surface or open-pit mining of loosely consolidated silica deposits and dredge mining. Silica mining and processing typically has less of an
environmental impact than the mining and processing of other minerals, in part because it uses fewer chemicals.

We maintain quality standards in all of our mining and processing facilities, some of which include International Organization for Standardization ("ISO")
9001-registered quality systems. We use automated process control systems that efficiently manage the majority of the mining and processing functions, and we
monitor the quality and consistency of our products by conducting hourly tests throughout the production process to detect variances. All of our major facilities
operate a testing laboratory to evaluate and ensure the quality of our products and services. We also provide customers with documentation verifying that all
products shipped meet customer specifications. These quality assurance functions are designed to ensure that we deliver quality products to our customers and
maintain customer trust and loyalty.

Our Customers

We sell our products to a variety of end markets. Our customers in the oil and gas proppants end market include major oilfield services companies and
exploration and production companies that are engaged in hydraulic fracturing. Sales to the oil and gas proppants end market comprised approximately 63%,
56%, and 49% of our total sales in 2022, 2021 and 2020, respectively.

During most of our 123-year history, our primary markets have been core industrial end markets with customers engaged in the production of building

and construction products, fillers and extenders, glass, foundry products, chemicals, and sports and recreation products. Our diverse customer base drives high
recovery rates across our production. We also benefit from strong and long-standing relationships with our customers in each of the industrial and specialty
products end markets we serve. Through EPM, we also serve a variety of industrial mineral markets including pool filtration, paints and plastics, absorbents and
food and beverage. Sales to our Industrial and Specialty Products end markets comprised approximately 37%, 44%, and 51% of our total sales in 2022, 2021
and 2020, respectively.

Competition

Both of our reportable segments operate in highly competitive markets that are characterized by a small number of large, national producers and a larger

number of small, regional or local producers. According to a January 2023 publication by the United States Geological Survey, in 2022, there were 122
producers of commercial silica with a combined 201 active operations in 32 states within the United States. Competition for both of our reportable segments is
based on price, consistency and quality of product, site location, distribution capability, customer service, reliability of supply, breadth of product offering and
technical support. Because transportation costs can be a significant portion of the total cost to customers of commercial

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silica, the commercial silica market is typically local, and competition from beyond the local area is limited. Notable exceptions to this are the frac sand and
fillers and extenders markets, where certain product characteristics are not available in all deposits and not all plants have the requisite processing capabilities,
necessitating that some products be shipped for extended distances. For more information regarding competition, see Item 1A. Risk Factors of this Annual
Report on Form 10-K. 

Seasonality

Our business is affected to some extent by seasonal fluctuations in weather that impact our production levels and our customers' business needs. For example,
during the second and third quarters we typically sell more commercial silica to our customers in the building products and recreation end markets due to
increased construction activity resulting from more favorable weather. In the first and fourth quarters, we generally experience lower sales, and sometimes
production levels, largely from adverse weather hampering logistical capabilities and general decreased customer activity levels.

Intellectual Property

Other than operating licenses for our mining and processing facilities, there are no third-party patents, patent licenses or franchises material to our

business. Our intellectual property primarily consists of trade secrets, know-how and trademarks, including our name US SILICA® and products with
trademarked names such as MIN-U-SIL®, Mystic White II®, Q-ROK®, SIL-CO-SIL®, White Armor®, EP Minerals®, EVERWHITE®, and SANDBOX®
among others. We own patents and have patent applications pending related to SandBox, our "last mile" logistics solution. Most of the issued patents have
expiration dates ranging from 2027-2040. With respect to our other products, we principally rely on trade secrets, rather than patents, to protect our proprietary
processes, methods, documentation and other technologies, as well as certain other business information. Although we do seek patents from time to time, for
example for our ultra-high reflectance cool roofing granules, patent protection for other industrial and specialty products requires a costly federal registration
process with an uncertain outcome that would place our confidential information in the public domain. As a result, we typically utilize trade secrets to protect
the formulations and processes we use to manufacture our products and to safeguard our proprietary formulations and methods. We strive to protect our trade
secrets indefinitely through the use of confidentiality agreements and other security measures, understanding that these efforts may prove to be ineffective. See
Item 1A. Risk Factors of this Annual Report on Form 10-K for more information.

Condition of Physical Assets and Insurance

Our business is capital intensive and requires ongoing capital investment for the replacement, modernization and/or expansion of equipment and facilities.

For more information, see Part II, Item 7. Management’s Discussion and Analysis of Financial Condition and Results of Operations - Liquidity and Capital
Resources of this Annual Report on Form 10-K.

We maintain insurance policies against property loss and business interruption and insure against other risks that are typical in the operation of our
business, in amounts that we believe to be reasonable. Such insurance, however, contains exclusions and limitations on coverage, particularly with respect to
environmental liability and political risk. There can be no assurance that claims would be paid under such insurance policies in connection with a particular
event. See Item 1A. Risk Factors of this Annual Report on Form 10-K for more information.

 Employees

As of December 31, 2022, we employed a workforce of approximately 2,013 employees, the majority of whom are hourly wage plant workers living in

the areas surrounding our mining facilities. Approximately 28% of our hourly employees are represented by labor unions that include the Teamsters Union;
United Steel, Paper and Forestry, Rubber, Manufacturing, Energy, Allied Industrial and Service Workers International Union; Laborers International Union of
North America; Glass, Molders, Pottery, Plastics and Allied Workers International Union; Cement, Lime, Gypsum and Allied Workers’ Division of
International Brotherhood of Boilermakers, Iron Ship Builders, Blacksmiths, Forgers and Helpers; and International Union of Operating Engineers A.F.L. -
C.I.O. We believe that we maintain good relations with our workers and their respective unions and have not experienced any material strikes or work stoppages
since 1987.

Human Capital Management

Our Board of Directors believes that our long-term success depends on the talents of our employees, and we work to attract, retain and motivate the

highest quality workforce. Our Chief Operating Officer ("COO"), with the support of members of our Human Resources team, is responsible for developing and
executing our human capital strategy. This includes talent attraction, acquisition, development and engagement, as well as the design of employee compensation
and benefits programs. It also includes developing and implementing our diversity and inclusion framework. Management regularly updates our Board of

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Directors and our Compensation Committee on human capital trends and efforts to improve diversity. The Board of Directors in particular has requested
updates on the following topics:

Health and Safety: Our health and safety programs are industry leading and resulted in several company records in 2022. We require each of our
locations to perform regular safety audits to ensure proper safety policies, program procedures, analyses and trainings are in place. In addition, we receive
regular visits from inspectors on behalf of the U.S. Mine Safety and Health Administration ("MSHA") and the U.S. Occupational Safety and Health Act
("OSHA"). We utilize a mixture of leading and lagging indicators to assess the health and safety performance of our operations. Lagging indicators include the
OSHA Total Recordable Incident Rate ("TRIR") and the Lost Time (or Lost Workday) Incident Rate ("LTIR") based upon the number of incidents per 200,000
work hours. Leading indicators include reporting and closure of all near miss events and Environmental, Health and Safety ("EHS") coaching and engagement
conversations. In 2022, we had a TRIR of 0.61, a LTIR of 0.14 and zero work-related fatalities.

Diversity, Inclusion, and Belonging: We believe that a culture of inclusion, diversity, and belonging enables us to create, develop and fully leverage the

strengths of our workforce. Current key initiatives include mandatory unconscious bias training for all employees, partnerships with diversity organizations,
improving purchasing from Minority and Women Owned Businesses, utilizing an employee driven resource group, and diverse talent acquisition practices. We
have implemented several measures that focus on ensuring accountabilities exist for making progress in diversity, and our senior leaders will have diversity and
inclusion objectives embedded in their annual performance goals.

Training and Talent Development: We are committed to the continued development of our people. Strategic talent reviews and succession planning

occur annually and across all business areas. The Chief Executive Officer ("CEO") and COO convene meetings with senior company leadership and the Board
of Directors to review top enterprise talent. We also provide free training courses through LinkedIn Learning to all salaried employees, along with key
development programs.

Regulation and Legislation

Mining and Workplace Safety

Federal Regulation

The U.S. Mine Safety and Health Administration (“MSHA”) is the primary regulatory organization governing the commercial silica industry.

Accordingly, MSHA regulates quarries, surface mines, underground mines and the industrial mineral processing facilities associated with quarries and mines.
The mission of MSHA is to administer the provisions of the Federal Mine Safety and Health Act of 1977 (the "Mine Act") and to enforce compliance with
mandatory safety and health standards. MSHA works closely with the Industrial Minerals Association, a trade association in which we have a significant
leadership role, in pursuing this mission. As part of MSHA’s oversight, representatives perform at least two unannounced inspections annually for each above-
ground facility. For additional information regarding mining and workplace safety, including MSHA safety and health violations and assessments in 2022, see
Item 4. Mine Safety Disclosures of this Annual Report on Form 10-K.

We also are subject to the requirements of the U.S. Occupational Safety and Health Act (“OSHA”) and comparable state statutes that regulate the

protection of the health and safety of workers. In addition, the OSHA Hazard Communication Standard requires that information be maintained about
hazardous materials used or produced in operations and that this information be provided to employees, state and local government authorities and the public.
OSHA regulates the customers and users of commercial silica and provides detailed regulations requiring employers to protect employees from overexposure to
silica bearing dust through the enforcement of permissible exposure limits and the OSHA Hazard Communication Standard.

Internal Controls

We adhere to a strict occupational health program aimed at controlling exposure to silica bearing dust, which includes dust sampling, a respiratory
protection program, medical surveillance, training and other components. Our safety program is designed to ensure compliance with the standards of our
Occupational Health and Safety Manual and MSHA regulations. For both health and safety issues, extensive training is provided to employees. We have safety
committees at our plants made up of salaried and hourly employees. We perform annual internal health and safety audits and conduct annual crisis management
drills to test our plants’ abilities to respond to various situations. Health and safety programs are administered by our corporate health and safety department
with the assistance of plant Environmental, Health and Safety Coordinators.

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Motor Carrier Regulation

Our trucking services are regulated by the U.S. Department of Transportation ("DOT"), the Federal Motor Carrier Safety Administration ("FMCSA") and
by various state agencies. These regulatory authorities have broad powers, generally governing matters such as authority to engage in motor carrier operations,
as well as motor carrier registration, driver hours of service, safety and fitness of transportation equipment and drivers, transportation of hazardous materials
and periodic financial reporting. The transportation industry is subject to possible other regulatory and legislative changes (such as the possibility of more
stringent environmental, climate change, security and/or occupational safety and health regulations, limits on vehicle weight and size and a mandate to
implement electronic logging devices) that may affect the economics of our trucking services by requiring changes in operating practices or by changing the
demand for motor carrier services or the cost of providing truckload or other transportation or logistics services.

Environmental Matters

We and the commercial silica industry in general are subject to extensive governmental regulations on, among other things, matters such as permitting
and licensing requirements, plant and wildlife protection, hazardous materials, air and water emissions and environmental contamination and reclamation. A
variety of state, local and federal agencies enforce these regulations.

Federal Regulation

At the federal level, we may be required to obtain permits under Section 404 of the Clean Water Act from the U.S. Army Corps of Engineers for the

discharge of dredged or fill material into waters of the United States, including wetlands and streams, in connection with our operations. We also may be
required to obtain permits under Section 402 of the Clean Water Act from the U.S. Environmental Protection Agency (“EPA”) (or the relevant state
environmental agency in states where the permit program has been delegated to the state) for discharges of pollutants into waters of the United States, including
discharges of wastewater or storm water runoff associated with construction activities. Failure to obtain these required permits or to comply with their terms
could subject us to administrative, civil and criminal penalties as well as injunctive relief.

The federal Safe Drinking Water Act (the “SDWA”) regulates the underground injection of substances through the Underground Injection Control
Program (the “UIC Program”). Hydraulic fracturing generally has been exempt from federal regulation under the UIC Program, and the hydraulic fracturing
process has been typically regulated by state or local governmental authorities. The EPA, however, has taken the position that certain aspects of hydraulic
fracturing with fluids containing diesel fuel may be subject to regulation under the UIC Program, specifically as “Class II” UIC wells. In February 2014, the
EPA released an interpretive memorandum to clarify UIC Program requirements under the SDWA for underground injection of diesel fuels in hydraulic
fracturing for oil and gas extraction and issued technical guidance containing recommendations for EPA permit writers to consider in implementing these UIC
“Class II” requirements. Among other things, the memorandum and technical guidance clarified that any owner or operator who injects diesel fuels in hydraulic
fracturing for oil or gas extraction must obtain a UIC “Class II” permit before injection.

The U.S. Clean Air Act and comparable state laws regulate emissions of various air pollutants through air emissions permitting programs and the

imposition of other requirements. These regulatory programs may require us to install expensive emissions abatement equipment, modify our operational
practices and obtain permits for our existing operations, and before commencing construction on a new or modified source of air emissions, such laws may
require us to reduce emissions at existing facilities. As a result, we may be required to incur increased capital and operating costs because of these regulations.
We could be subject to administrative, civil and criminal penalties as well as injunctive relief for noncompliance with air permits or other requirements of the
U.S. Clean Air Act and comparable state laws and regulations.

As part of our operations, we utilize or store petroleum products and other substances such as diesel fuel, lubricating oils and hydraulic fluid. We are

subject to applicable requirements regarding the storage, use, transportation and disposal of these substances, including the relevant Spill Prevention, Control
and Countermeasure requirements that the EPA imposes on us. Spills or releases may occur in the course of our operations, and we could incur substantial costs
and liabilities as a result of such spills or releases, including those relating to claims for damage or injury to property and persons.

Additionally, some of our operations are located on properties that historically have been used in ways that resulted in the release of contaminants,

including hazardous substances, into the environment, and we could be held liable for the remediation of such historical contamination. The Comprehensive
Environmental Response, Compensation and Liability Act (“CERCLA”), also known as the Superfund law, and comparable state laws impose joint and several
liability, without regard to fault or legality of conduct, on classes of persons who are considered to be responsible for the release of hazardous substances into
the environment. These persons include the owner or operator of the site where the release occurred and anyone who disposed or arranged for the disposal of a
hazardous substance released at the site. Under CERCLA, such persons may be subject to liability

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for the costs of cleaning up the hazardous substances, for damages to natural resources, and for the costs of certain health studies. In addition, it is not
uncommon for neighboring landowners and other third parties to file claims for personal injury and property damage allegedly caused by the hazardous
substances released into the environment.

In addition, the Resource Conservation and Recovery Act (“RCRA”) and comparable state statutes regulate the generation, transportation, treatment,

storage, disposal and cleanup of hazardous and non-hazardous wastes. Under the auspices of the EPA, the individual states administer some or all of the
provisions of RCRA, sometimes in conjunction with their own, more stringent requirements. In the course of our operations, we generate industrial solid wastes
that may be regulated as hazardous wastes.

Our operations may also be subject to broad environmental review under the National Environmental Policy Act (“NEPA”). NEPA requires federal

agencies to evaluate the environmental impact of all “major federal actions” significantly affecting the quality of the human environment. The granting of a
federal permit for a major development project, such as a mining operation, may be considered a “major federal action” that requires review under NEPA.
Therefore, our projects may require review and evaluation under NEPA.

Federal agencies granting permits for our operations must also consider impacts to endangered and threatened species and their habitat under the

Endangered Species Act. We also must comply with and are subject to liability under the Endangered Species Act, which prohibits and imposes stringent
penalties for the harming of endangered or threatened species and their habitat. Federal agencies must also consider a project’s impacts on historic or
archaeological resources under the National Historic Preservation Act, and we may be required to conduct archaeological surveys of project sites and to avoid
or preserve historical areas or artifacts.

State and Local Regulation

Because our operations are located in numerous states, we are also subject to a variety of different state and local environmental review and permitting

requirements. Some states in which our projects are located or are being developed have state laws similar to NEPA; thus, our development of new sites or the
expansion of existing sites may be subject to comprehensive state environmental reviews even if they are not subject to NEPA. In some cases, the state
environmental review may be more stringent than the federal review. Our operations may require state law based permits in addition to federal permits,
requiring state agencies to consider a range of issues, many the same as federal agencies, including, among other things, a project’s impact on wildlife and their
habitats, historic and archaeological sites, aesthetics, agricultural operations and scenic areas. Some states also have specific permitting and review processes
for commercial silica mining operations, and states may impose different or additional monitoring or mitigation requirements than federal agencies. The
development of new sites and our existing operations also are subject to a variety of local environmental and regulatory requirements, including land use,
zoning, building and transportation requirements.

As demand for frac sand in the oil and natural gas industry has driven a significant increase in current and expected future production of commercial

silica, some local communities have expressed concern regarding silica sand mining operations. These concerns have generally included exposure to ambient
silica sand dust, truck traffic, water usage and blasting. In response, certain state and local communities have developed or are in the process of developing
regulations or zoning restrictions intended to minimize dust from getting airborne, control the flow of truck traffic, significantly curtail the amount of
practicable area for mining activities, provide compensation to local residents for potential impacts of mining activities and, in some cases, ban issuance of new
permits for mining activities. To date, we have not experienced any material impact or disruption to our existing mining operations or planned capacity
expansions as a result of these types of concerns.

We have a long history of positive engagement with the communities that surround our existing mining operations. We believe our relatively stable

workforce and strong relationship with our employees help foster good relations with the communities in which we operate. Although additional regulatory
requirements could negatively impact our business, financial condition and results of operations, we believe our existing operations may be less likely to be
negatively impacted by virtue of our good community relations.

Planned expansion of our mining and production capacity in new communities could be more significantly impacted by increased regulatory activity.

Difficulty or delays in obtaining or inability to obtain new mining permits or increased costs of compliance with future state and local regulatory requirements
could have a material negative impact on our ability to grow our business. In an effort to minimize these risks, we continue to be engaged with local
communities in order to grow and maintain strong relationships with residents and regulators.

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Costs of Compliance

We may incur significant costs and liabilities as a result of environmental, health and safety requirements applicable to our activities. Failure to comply
with environmental laws and regulations may result in the assessment of administrative, civil and criminal penalties, imposition of investigatory, cleanup and
site restoration costs and liens, the denial or revocation of permits or other authorizations and the issuance of injunctions to limit or cease operations.
Compliance with these laws and regulations may also increase the cost of the development, construction and operation of our projects and may prevent or delay
the commencement or continuance of a given project. In addition, claims for damages to persons or property may result from environmental and other impacts
of our activities.

The process for performing environmental impact studies and reviews for federal, state and local permits for our operations involves a significant
investment of time and monetary resources. We cannot control the permit approval process. We cannot predict whether all permits required for a given project
will be granted or whether such permits will be the subject of significant opposition. The denial of a permit essential to a project or the imposition of conditions
with which it is not practicable or feasible to comply could impair or prevent our ability to develop a project. Significant opposition and delay in the
environmental review and permitting process also could impair or delay our ability to develop a project. Additionally, the passage of more stringent
environmental laws could impair our ability to develop new operations and have an adverse effect on our financial condition and results of operations We do not
expect any material capital expenditures due to current regulatory compliance obligations.

Availability of Reports; Website Access; Other Information

Our Internet address is http://www.ussilica.com. Through “Investors” — “Financial Information” on our home page, we make available free of charge our

annual reports on Form 10-K, our quarterly reports on Form 10-Q, our proxy statements, our current reports on Form 8-K, SEC Forms 3, 4 and 5 and any
amendments to those reports filed or furnished pursuant to Sections 13(a) or 15(d) of the Exchange Act as soon as reasonably practicable after we electronically
file such material with, or furnish it to, the SEC. Our reports filed with the SEC are also available on its website at http://www.sec.gov.

Stockholders may also request a free copy of these documents from: U.S. Silica Holdings, Inc., attn.: Investor Relations, 24275 Katy Freeway, Suite 600,

Katy, Texas 77494.

Information about our Executive Officers

Bryan A. Shinn, age 61, has served as our Chief Executive Officer and a member of the Board since January 2012. He also served as our President

from March 2011 to January 2020. Prior to assuming this position, Mr. Shinn was our Senior Vice President of Sales and Marketing from October 2009 to
February 2011. Before joining us, Mr. Shinn was employed by the E. I. du Pont de Nemours and Company from 1983 to September 2009, where he held a
variety of key leadership roles in operations, sales, marketing and business management, including Global Business Director and Global Sales Director.
Mr. Shinn earned a B.S. in Mechanical Engineering from the University of Delaware.

Donald A. Merril, age 58, has served as an Executive Vice President since July 2016 and as our Chief Financial Officer since January 2013. He had
previously served as our Vice President of Finance from October 2012 until his appointment as Chief Financial Officer. Previously, Mr. Merril had served as
Senior Vice President and Chief Financial Officer of Myers Industries Inc. from January 2006 through August 2012. Prior to serving at Myers Industries,
Mr. Merril held the role of Vice President and Chief Financial Officer, Rubbermaid Home Products Division at Newell Rubbermaid Inc. from 2003 through
2005. Mr. Merril earned a B.S. in Accounting from Miami University.

Michael L. Winkler, age 58, has served as an Executive Vice President since July 2016 and as our Chief Operating Officer since December 2013. He

served as a Vice President from June 2011 until July 2016 and as our Vice President of Operations from June 2011 until December 2013. Before joining us,
Mr. Winkler was Vice President of Operations for Campbell Soup Company from August 2007 to June 2011 and held various positions with Mars Inc. from
1996 to August 2007, including Plant Manager-Columbus Plant and Director of Industrial Engineering. Mr. Winkler earned a B.S. in Industrial Engineering
from the University of Wisconsin-Platteville and an M.B.A. from the University of North Texas. In January 2023, Mr. Winkler notified us of his plan to retire.
Mr. Winkler is expected to remain in his position until mid to late 2023 to assist wth the transition of his responsibilities.

Zach Carusona, age 36, was appointed as our Executive Vice President and President, Industrial & Specialty Products in August 2022. He served as

Senior Vice President and President, Specialty Minerals from December 2018 until July 2022, Vice President of SandBox Logistics from August 2016 until
December 2018, the Director, Strategic Planning from June 2015 to August 2016, and in various roles in our strategy group from 2011 through 2015. Mr.
Carusona earned an MBA from

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the Kellogg School of Management at Northwestern University, and a B.S. in Mechanical Engineering from the University of Illinois, Urbana-Champaign.

J. Derek Ussery, age 38, was appointed as our Executive Vice President and President, Oil and Gas in August 2022. He served as the Senior Vice
President and President, Oil and Gas from November 2019 to July 2022 and Chief Operating Officer of SandBox Logistics from January 2019 to November
2019. He previously served as Vice President, North America ESG at Tetra Technologies, from May 2018 to December 2018. From April 2013 to May 2018, he
served in roles of increasing responsibility with Key Energy Services, culminating in his position as Vice President for the Eastern Region. Mr. Ussery earned a
B.B.A. from Texas A&M University.

Stacy Russell, age 52, has served as U.S. Silica’s Senior Vice President, General Counsel and Secretary since January 2020. Prior to this role, Ms.
Russell was the General Counsel for our Oil & Gas Proppants segment. She was previously Of Counsel at Boyar Millar from July 2018 to May 2019. From
October 2010 to January 2018, she served as the Managing Counsel for the Litigation and HSE law groups at Halliburton Company. Ms. Russell earned B.A. in
Government from the University of Texas and her J.D. from the University of Houston.

ITEM 1A.

RISK FACTORS

Our operations and financial results are subject to various risks and uncertainties, including those described below and elsewhere in this Annual Report
on Form 10-K. You should carefully consider the risk factors set forth below as well as the other information contained in this Annual Report on Form 10-K in
connection with evaluating our business and our securities. The categorization of risks set forth below is meant to help you better understand the risks facing
our business and is not intended to limit consideration of the possible effects of these risks to the listed categories, nor is it meant to imply that one category of
risks is more material than another. Any adverse effects related to the risks discussed below may, and likely will, adversely affect many aspects of our business.

Additional risks and uncertainties not currently known to us or that we currently deem to be immaterial may also materially and adversely affect our stock

price, business, results of operations or financial condition. Certain statements in these risk factors are forward-looking statements.

Risks Related to Market, Competition, & Sales

The global economic environment has recently created market uncertainty and volatility.

The global economic environment has recently created market uncertainty and volatility. Global financial conditions remain subject to sudden and rapid

destabilization. A slowdown in the financial markets or other economic conditions, including but not limited to, global supply chain issues, inflation, increasing
interest rates, fuel and energy costs, business conditions, lack of available credit, the state of the financial markets and tax rates, may adversely affect our
business, financial condition and results of operations.

Our frac sand mining and logistics operations depend on the level of activity in the oil and natural gas industries, which experience substantial

volatility.

Our operations that produce and transport frac sand are materially dependent on the levels of activity in natural gas and oil exploration, development and

production. More specifically, the demand for the frac sand we produce is closely related to the number of natural gas and oil wells completed in geological
formations where sand-based proppants are used in fracture treatments. These activity levels are affected by both short- and long-term trends in natural gas and
oil prices. In recent years, natural gas and oil prices and, therefore, the level of exploration, development and production activity, have experienced significant
volatility. 

When oil and natural gas prices decrease, exploration and production companies may reduce their exploration, development, production and well

completion activities. During such periods, demand for our products and services which supply oil and natural gas wells, including our transportation and
logistics solutions, may decline, leading to a decline in the market price of frac sand due to an oversupply of frac sand. When demand for frac sand increases,
there may not be a corresponding increase in the prices for our products or our customers may not increase use of our products, which could have a material
adverse effect on our business, financial condition and results of operations.

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Worldwide economic, political and military events, including war, terrorist activity, events in the Middle East and initiatives by the Organization of the
Petroleum Exporting Countries (“OPEC”), have contributed, and are likely to continue to contribute, to oil and natural gas price volatility. Additionally, warmer
than normal winters in North America and other weather patterns may adversely impact the short-term demand for natural gas and, therefore, demand for our
products. Reduction in demand for natural gas to generate electricity could also adversely impact the demand for frac sand. In addition, any future decrease in
the rate at which oil and natural gas reserves are discovered or developed, whether due to increased governmental regulation, limitations on exploration and
drilling activity, technological innovations that result in new processes for oil and gas production that do not require proppants, or other factors, could adversely
affect the demand for our products, even in a stronger natural gas and oil price environment. The continued or future occurrence of any of these risks could have
a material adverse effect on our business, financial condition and results of operations.

A public health crisis or global outbreak of disease could materially and adversely affect our business, financial condition and results of operations.

A public health crisis, including the COVID-19 pandemic and the emergence and spread of COVID-19 variants, have previously adversely impacted our
business and results of operations. A public health crisis, including a pandemic similar in nature to COVID-19, could affect our business in a number of ways,
including but not limited to:

• disruptions or restrictions on our employees' ability to work;
• temporary closures or disruptions at our mines and processing plants or the facilities of our customers could reduce         demand for our products or

affect our ability to timely meet our customers' orders and negatively impact our supply chain; and

• the failure of third parties on which we rely, including our customers, contractors, commercial banks, transportation service providers and external
business partners, to meet their respective obligations to us, or significant disruptions in their ability to do so, which may be caused by their own
financial or operational difficulties.

The impact of contagious disease or other adverse public health developments could also exacerbate other risks discussed elsewhere in this section of this

report, any of which could have a material adverse effect on us.

Our industrial materials operations are subject to the cyclical nature of our customers’ businesses.

The majority of our industrial products customers are engaged in industries that have historically been cyclical, such as glassmaking, building products,

foundry products, and paint. During periods of economic slowdown in one or more of the industries or geographic regions we serve or in the worldwide
economy, our customers often reduce their production and capital expenditures by deferring or canceling pending projects, even if such customers are not
experiencing financial difficulties. These developments can have an adverse effect on sales of our products and our results of operations.

Demand in many of the end markets for our industrial products is driven by cyclical industries, such as construction and automotive. For example, the flat

glass market depends on the automotive and commercial and residential construction and remodeling markets; the market for commercial silica used to
manufacture building products is driven primarily by demand in the construction markets; the market for foundry silica depends on the rate of automobile, light
truck and heavy equipment production as well as construction; and the market for diatomaceous earth, perlite, clay and cellulose is driven by agricultural, food
and beverage, chemical industries, filtration, catalyst and absorbent applications. When demand from one of these cyclical industries decreases, demand for the
products we sell to customers in that industry may also decrease. When demand from one of these cyclical industries increases, however, there may not be a
corresponding increase in the prices for our products or our customers may not increase the use of our products due to factors such as the use of recycled glass
in glass production; substitution of our products for other materials; changes in residential and commercial construction demands, driven in part by fluctuating
interest rates and demographic shifts; prices, availability and other factors relating to our products; competitors both locally and internationally; and other
factors.

Weakness in the industries we serve has had, and may have in the future, an adverse effect on sales and our results of operations. A continued or renewed
economic downturn in one or more of the industries or geographic regions that we serve, or in the worldwide economy, could cause actual results of operations
to differ materially from historical and expected results.

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Our sales, profitability and operations could be materially affected by weather conditions, seasonality and other factors.

Our sales and profitability from period to period are affected by a variety of factors, including weather conditions and seasonal periods. As a result, our
results of operations may fluctuate on a quarterly basis and relative to corresponding periods in prior years. For example, we sell more of our products in the
second and third quarters in the building products and recreation end markets due to the seasonal rise in construction driven by more favorable weather
conditions. Conversely, we sell fewer of our products in the first and fourth quarters in these end markets due to reduced construction and recreational activity
largely as a result of adverse weather conditions. These fluctuations in our operating results may render period-to-period comparisons less meaningful, and
investors in our securities should not rely on the results of any one period as an indicator of performance in any other period.

In addition, severe seasonal or weather conditions may impact our operations by causing weather-related damage to our facilities and equipment or
preventing us from delivering equipment, personnel or products to job sites, any of which could force us to delay or curtail services and potentially breach our
contractual obligations or result in a loss of productivity, an increase in operating costs or other losses that may not be covered by applicable insurance policies.
Severe weather conditions may also interfere with our customers’ operations, which could reduce our customers’ demand for our products. If any of these risks
were to occur, it could have a material adverse effect on our business, financial condition and results of operations. Moreover, changing weather patterns, due to
climate-warming trends and other effects of climate change or other causes, may lead to the increased frequency, severity or unpredictability of extreme weather
events, which could intensify these risks.

A significant portion of our sales is generated at four of our plants. Any adverse developments at any of those plants or in the end markets those plants

serve could have a material adverse effect on our business, financial condition, and results of operations.

A significant portion of our sales is generated at our plants located in Ottawa, Illinois; Lamesa, Texas; Lovelock, Nevada; and Crane County, Texas.
These plants represented a combined 29% of our total sales in 2022. Any adverse development at these plants or in the end markets these plants serve, including
adverse developments due to catastrophic events or weather, decreased demand for commercial silica products, or a decrease in the availability of transportation
services or adverse developments affecting our customers, could have a material adverse effect on our business, financial condition and results of operations.

We may be adversely affected by decreased demand for frac sand or the development of effective alternative proppants or new processes to replace

hydraulic fracturing.

Frac sand is a proppant used in the completion and re-completion of natural gas and oil wells through hydraulic fracturing. Frac sand is the most
commonly used proppant and is less expensive than ceramic proppant, which is also used in hydraulic fracturing to stimulate and maintain oil and natural gas
production. A significant shift in demand from frac sand to other proppants, such as ceramic proppants, the development and use of other effective alternative
proppants, or the development of new alternative energy processes to replace hydraulic fracturing altogether, could cause a decline in demand for the frac sand
we produce and could have a material adverse effect on our business, financial condition and results of operations.

Our future performance will depend on our ability to succeed in competitive markets, and on our ability to appropriately react to potential fluctuations

in demand for and supply of our products.

We operate in a highly competitive market that is characterized by a small number of large, national producers and a larger number of small, regional or

local producers. Competition in the industry is based on price, consistency and quality of product, site location, distribution capability, customer service,
reliability of supply, breadth of product offering and technical support. Because transportation costs are a significant portion of the total cost to customers of
commercial silica (in many instances transportation costs can represent more than 50% of delivered cost), the commercial silica market is typically local, and
competition from beyond the local area is limited. Notable exceptions to this are the frac sand and fillers and extenders markets, where certain product
characteristics are not available in all deposits and not all plants have the requisite processing capabilities, necessitating that some products be shipped for
extended distances.

Because the markets for our products are typically local, we also compete with smaller, regional or local producers in addition to the other national
producers. There typically is an increasing number of small producers servicing the frac sand market when there is increased demand for hydraulic fracturing
services. If demand for hydraulic fracturing services decreases and the supply of frac sand available in the market increases, prices in the frac sand market could
continue to materially decrease as less efficient producers exit the market, selling frac sand at below market prices. Furthermore, our competitors may

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choose to consolidate, which could provide them with greater financial and other resources than us and negatively impact demand for our frac sand products. In
addition, oil and natural gas exploration and production companies and other providers of hydraulic fracturing services may acquire their own frac sand
reserves, expand their existing frac sand production capacity or otherwise fulfill their own proppant requirements, and existing or new frac sand producers could
add to or expand their frac sand production capacity, which would negatively impact demand for our frac sand products.

With regards to our international sales and operations, our performance is also subject to currency exchange fluctuations. In addition, our ability to sell

and deliver our products to, and collect payment from, our international customers depends on fund transfer and trade restrictions and import/export duties, the
ability to import and export goods, and fluctuating policies on tariffs on a number of goods that could impact our operations. These factors and uncertainties
may cause our international customers to seek out producers who are not located in the United States to fulfill their commercial silica requirements or may
otherwise make it more difficult for us to compete with international producers.

If our customers delay or fail to pay a significant amount of our outstanding receivables, it could have a material adverse effect on our business,

liquidity, financial condition and results of operations.

We bill our customers for our products in arrears and are, therefore, subject to credit risks if our customers delay or fail to pay our invoices. In weak
economic environments, we have experienced increased delays or failures due to, among other reasons, a reduction in our customers’ cash flow from operations
and ability to access the credit markets. In addition, some of our customers have experienced financial difficulties, including insolvency or bankruptcy
proceedings, in which cases we have not been able to collect sums owed to us or have received significantly less than expected, and we may be required to
refund pre-petition amounts paid to us during a specified period prior to the bankruptcy filing. Furthermore, we may experience longer collection cycles with
our international customers due to foreign fund transfer restrictions, and we may have difficulty enforcing agreements and collecting accounts receivable from
our international customers through a foreign country’s legal system. If our customers delay or fail to pay us a significant amount of our outstanding
receivables, it could have a material adverse effect on our business, liquidity financial condition, and results of operations.

A large portion of our sales is generated by our top ten customers, and the loss of or a significant reduction in purchases by our largest customers

could adversely affect our results of operations.

Our ten largest customers accounted for approximately 40%, 40% and 34% of total sales during the years ended December 31, 2022, 2021 and 2020,
respectively. As a result of market conditions, competition or other factors, these customers may not continue to purchase the same levels of our products in the
future, if at all. Substantial reductions in purchase volumes across these customers could have a material adverse effect on our business, financial condition and
results of operations.

Operational Risks

Our operations are subject to risks and dangers inherent to mining, some of which are beyond our control, and some of which may not be covered by

insurance.

Our mining, processing and production facilities are subject to risks normally encountered in the commercial silica and earth minerals industries, many of

which are not in our control. In addition to the other risks described in these risk factors, these risks include:

•
•
•
•
•
•
•
•
•
•
•
•
•

unanticipated ground, grade or water conditions;
unusual or unexpected geological formations or pressures;
pit wall failures, underground roof falls or surface rock falls;
environmental hazards;
physical plant security breaches;
inability to acquire or maintain necessary permits or mining or water rights;
failure to maintain dust controls and meet restrictions on respirable crystalline silica dust;
restrictions on blasting operations;
failures in quality control systems or training programs;
technical difficulties or key equipment failures;
inability to obtain necessary mining or production equipment or replacement parts;
fires, explosions or industrial accidents or other accidents; and
facility shutdowns in response to environmental regulatory actions.

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Any of these risks could result in damage to, or destruction of, our mining properties or production facilities, personal injury, environmental damage,

delays in mining or processing, losses or possible legal liability. Any prolonged downtime or shutdowns at our mining properties or production facilities could
have a material adverse effect on our business, financial condition, and results of operations.

Not all of these risks are reasonably insurable, and our insurance coverage contains limits, deductibles, exclusions and endorsements. Our insurance
coverage may not be sufficient to meet our needs in the event of loss and any such loss may have a material adverse effect on our business, financial condition
and results of operations.

Diminished access to water may adversely affect our operations.

The mining and processing activities in which we engage at a number of our facilities require significant amounts of water, and some of our facilities are

located in areas that are water-constrained. We may not be able obtain water rights sufficient to service our current activities or to service any properties we may
develop or acquire in the future. Moreover, the amount of water we are entitled to use pursuant to our water rights must be determined by the appropriate
regulatory authorities, and these authorities may amend the regulations affecting our water rights, increase the cost of maintaining our water rights or reduce or
eliminate our existing water rights, in which case we may be unable to retain these rights. Furthermore, our existing water rights could be disputed. Any such
changes in laws, regulations or government policy and related interpretations pertaining to water rights or any successful claim that we lack appropriate water
rights may alter our operating costs or the environment in which we do business, which may negatively affect our financial condition and results of operations.

Increasing costs, a lack of dependability or availability of transportation services, transload network access or infrastructure or an oversupply of

transportation services could have a material adverse effect on our business, financial condition, and results of operations.

Because of the relatively low cost of producing commercial silica, transportation and related costs, including freight charges, fuel surcharges, transloading

fees, switching fees, railcar lease costs, demurrage costs and storage fees, tend to be a significant component of the total delivered cost of sales. The high
relative cost of transportation related expense tends to favor manufacturers located in close proximity to the customer. As a result, if we expand our commercial
silica production to new geographic markets, we could need increased transportation services and transload network access and would be subject to higher
overall costs for these services. We contract with truck, rail and barge services to move commercial silica from our production facilities to transload sites and
our customers, and increased costs under these contracts could adversely affect our results of operations. In addition, we bear the risk of non-delivery under our
contracts. Labor disputes, derailments, adverse weather conditions or other environmental events, shortages in the railcar leasing market or changes to rail
freight systems could interrupt or limit available transportation services. A significant increase in transportation service rates, a reduction in the dependability or
availability of transportation or transload services, or relocation of our customers’ businesses to areas farther from our plants or transloads could impair our
ability to deliver our products economically to our customers and to expand to new markets. Further, reduced demand for commercial silica sometimes results
in railcar over-capacity, requiring us to pay railcar storage fees while, at the same time, continuing to make lease payments for those railcars in storage, which
can have a material adverse effect on our business, financial condition and results of operations.

Our operations consume large amounts of natural gas, electricity and diesel fuel. An increase in the price or a significant interruption in the supply of

these or any other energy sources could have a material adverse effect on our business, financial condition, and results of operations.

Energy costs, primarily natural gas and electricity, represented approximately 5%, 5% and 4% of our total sales in 2022, 2021 and 2020, respectively.
Natural gas is the primary fuel source used for drying in the commercial silica production process. In addition, our operations are dependent on earthmoving
equipment, railcars and tractor trailers, and diesel fuel costs are a significant component of the operating expense of these vehicles. To the extent that we
perform these services with equipment that we own, we are responsible for buying and supplying the diesel fuel needed to operate these vehicles, which
currently represents less than 1% of total cost of sales. To the extent that these services are provided by independent contractors, we may be subject to fuel
surcharges that attempt to recoup increased diesel fuel expenses. Our profitability is impacted by the price and availability of these energy sources. The price
and supply of diesel fuel and natural gas are unpredictable and can fluctuate significantly based on international political and economic circumstances, as well
as other events outside our control, such as changes in supply and demand due to weather conditions, actions by OPEC and other oil and natural gas producers,
regional production patterns and environmental concerns. In addition, potential climate change regulations or carbon or emissions taxes could result in higher
production costs for energy, which may be passed on to us in whole or in part or could reduce supply. In the past, the price of natural gas has been extremely
volatile, and we believe this volatility may continue. In order to manage

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this risk, we have hedged natural gas prices through the use of derivative financial instruments and may enter into additional hedges in the future. However,
these measures carry different risks (including nonperformance by counterparties) and do not in any event entirely eliminate the risk of decreased margins as a
result of energy price increases. A significant increase in the price of energy that is not recovered through an increase in the price of our products or covered
through our hedging arrangements or an interruption in the supply of the energy sources we use could have a material adverse effect on our business, financial
condition and results of operations.

Certain of our contracts contain provisions requiring us to deliver products that meet certain specifications. Noncompliance with these contractual
obligations may result in penalties or termination of the agreements.

In certain instances, we commit to deliver products under penalty of nonperformance. These obligations can require that we deliver products or services
that meet certain specifications that a customer may designate. Our inability to meet these contract requirements may permit the counterparty to terminate the
agreements, return products that fail to meet a customer’s quality specifications, or require us to pay a fee equal to the difference between the amount contracted
for and the amount delivered. Further, we may not be able to sell some of our products developed for one customer to a different customer because the products
may be customized to meet specific customer quality specifications, and even if we are able to sell these products to another customer, our margin on these
products may be reduced. Moreover, any inability to deliver products or services that meet customer requirements could harm our relationships with these
customers and our reputation generally. In such events, our business, financial condition and results of operations may be materially adversely affected.

Inaccuracies in our estimates of mineral reserves and resource deposits, or deficiencies in our title to those deposits, could result in our inability to

mine the deposits or require us to pay higher than expected costs.

We base our mineral reserve and resource estimates on engineering, economic and geological data assembled and analyzed by our mining engineers,
which are reviewed periodically by outside firms. However, commercial silica reserve estimates can be imprecise and depend to some extent on statistical
inferences drawn from available drilling data, which may prove unreliable. There are numerous uncertainties inherent in estimating quantities and qualities of
commercial silica reserves and non-reserve commercial silica deposits and costs to mine recoverable reserves, many of which are beyond our control and any of
which could cause actual results to differ materially from our expectations. These uncertainties include:

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geological and mining conditions and/or effects from prior mining that may not be fully identified by available data or that may differ from
experience;
assumptions regarding the effectiveness of our mining, quality control and training programs;
assumptions concerning future prices of commercial silica products, operating costs, mining technology improvements, development costs and
reclamation costs; and
assumptions concerning future effects of regulation, including the issuance of required permits and taxes by governmental agencies.

    In addition, title to, and the area of, mineral properties and water rights may be disputed. Mineral properties sometimes contain claims or transfer histories
that examiners cannot verify. A successful claim that we do not have title to one or more of our properties or lack appropriate water rights could cause us to lose
any rights to explore, develop and extract any minerals on that property, without compensation for our prior expenditures relating to such property. Any
inaccuracy in our estimates related to our mineral reserves and non-reserve mineral deposits, or our title to such deposits, could result in our inability to mine
the deposits or require us to pay higher than expected costs.

Our business and operations could suffer in the event of cybersecurity breaches, information technology system failures, or network disruptions.

We rely on our information technology systems to process transactions, summarize our operating results and manage our business. Our information

technology systems are subject to damage or interruption from power outages; computer and telecommunications failures; computer viruses; cyberattack or
other security breaches; catastrophic events, such as fires, floods, earthquakes, tornadoes, hurricanes, acts of war or terrorism; and usage errors by our
employees. If our information technology systems are damaged or cease to function properly, we may need to make a significant investment to fix or replace
them, and we may suffer loss of critical data and interruptions or delays in our operations.

We have been the target of cyberattacks, and while to date none of these incidents has had a material impact on us, we expect to continue to be targeted in

the future. Our management team updates our Board of Directors quarterly on material cybersecurity risks which might impact us. Our risk and exposure to
these matters remains heightened because of, among other things, the evolving nature of these threats, the current global economic and political environment,
the outsourcing of some of

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our business operations, the ongoing shortage of qualified cybersecurity professionals, and the interconnectivity and interdependence of third parties to our
systems.

The systems we employ to detect and prevent cyberattacks may be insufficient to protect us from an incident or to allow us to minimize the magnitude

and effects of such incident for a significant period of time. The occurrence of a cyberattack, breach, unauthorized access, misuse, computer virus or other
cybersecurity event could jeopardize our systems or result in the unauthorized disclosure, gathering, monitoring, misuse, corruption, loss or destruction of
confidential and other information that belongs to us, our customers, our counterparties, third-party service providers or borrowers that is processed and stored
in, and transmitted through, our computer systems and networks. Any such event could result in significant losses, loss of customers and business opportunities,
reputational damage, litigation, regulatory fines, penalties or intervention, reimbursement or other compensatory costs, or otherwise adversely affect our
business, financial condition or results of operations.

Mine closures entail substantial costs, and if we close one or more of our mines sooner than anticipated, our results of operations may be adversely

affected.

We base our assumptions regarding the life of our mines on detailed studies that we perform from time to time, but our studies and assumptions do not

always prove to be accurate. If we close any of our mines sooner than expected, sales will decline unless we are able to increase production at any of our other
mines, which may not be possible. The closure of an open pit mine may also involve significant fixed closure costs, including accelerated employment legacy
costs, severance-related obligations, reclamation and other environmental costs and the costs of terminating long-term obligations, including energy contracts
and equipment leases. We accrue for the costs of reclaiming open pits, stockpiles, tailings ponds, roads and other mining support areas over the estimated
mining life of our properties. If we were to reduce the estimated life of any of our mines, the fixed mine closure costs could be applied to a shorter period of
production, which would increase production costs per ton produced and could materially and adversely affect our business, results of operations and financial
condition.

Applicable statutes and regulations require that mining property be reclaimed following a mine closure in accordance with specified standards and an
approved reclamation plan. The plan addresses matters such as the removal of facilities and equipment, re-grading, prevention of erosion and other forms of
water pollution, re-vegetation and post-mining land use. Complying with these plans has had, and will continue to have, a significant effect on our business.
Some environmental laws impose substantial penalties for noncompliance with a reclamation plan, and others, such as the CERCLA, impose strict, retroactive
and joint and several liability for the remediation of releases of hazardous substances. We may be required to post a surety bond or other form of financial
assurance equal to the anticipated cost of reclamation as set forth in the approved reclamation plan. The inability to acquire, maintain or renew such financial
assurances could subject us to fines or the revocation of our operating permits. The establishment of the final mine closure reclamation liability is based on
permit requirements and requires various estimates and assumptions, principally associated with reclamation costs and production levels. If our accruals for
expected reclamation and other costs associated with mine closures for which we will be responsible were later determined to be insufficient, our business,
results of operations and financial condition would be adversely affected.

Legal & Compliance Risks

We are subject to numerous environmental regulations that impose significant costs and liabilities, which could increase under potential future

regulations or more stringent enforcement of existing regulations.

We are subject to a variety of federal, state and local environmental laws and regulations affecting the mining and mineral processing industry, including,
among others, those relating to environmental permitting and licensing, plant and wildlife protection, wetlands protection, air and water emissions, greenhouse
gas emissions, water pollution, waste management, remediation of soil and groundwater contamination, land use, reclamation and restoration of properties,
hazardous materials and natural resources. These laws and regulations have had, and will continue to have, a significant effect on our business. Some
environmental laws impose substantial penalties for noncompliance, and others, such as CERCLA, impose strict, retroactive and joint and several liability for
the remediation of releases of hazardous substances.

Environmental requirements, and the interpretation and enforcement of these requirements, change frequently and have tended to become more stringent

over time. Future environmental laws and regulations could restrict our ability to expand our facilities or extract our mineral deposits or could require us to
acquire costly equipment or to incur other significant expenses in connection with our business. The costs associated with complying with such requirements,
could have a material adverse effect on our business, financial condition and results of operations.

For example, greenhouse gas emissions regulation is becoming more rigorous, and concerns about climate change could cause this trend to continue or

intensify. We expect to be required to report annual greenhouse gas emissions from our

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operations to the EPA, and additional greenhouse gas emission-related requirements are in various stages of development at the international, federal, state,
regional and local levels. The U.S. Congress has considered, and may adopt in the future, various legislative proposals to address climate change, including a
nationwide limit on greenhouse gas emissions. Any regulation of greenhouse gas emissions, including, for example, through a cap-and-trade system, technology
mandate, emissions tax, reporting requirement, new permit requirement or other program, could curtail our operations, significantly increase our operating
costs, impair demand for our products or otherwise adversely affect our business, financial condition, reputation and performance.

Additionally, various state, local and foreign governments have implemented, or are considering, increased regulatory oversight of hydraulic fracturing

through additional permitting requirements, operational restrictions, disclosure requirements and temporary or permanent bans on hydraulic fracturing. A
significant portion of our business supplies frac sand to hydraulic fracturing operators in the oil and natural gas industry. Although we do not directly engage in
hydraulic fracturing activities, our customers purchase our frac sand for use in their hydraulic fracturing operations. There is significant federal oversight of
these operations by the EPA, Bureau of Land Management (“BLM”), and Department of Energy (“DOE”). A number of local municipalities across the United
States have also instituted measures resulting in temporary or permanent bans on or otherwise limiting or delaying hydraulic fracturing in their jurisdictions.
Additionally, a number of states have enacted legislation or issued regulations that impose various disclosure requirements on hydraulic fracturing operators.
Such moratoriums, bans, disclosure obligations, and other regulatory actions could make it more difficult to conduct hydraulic fracturing operations and
increase our customers’ cost of doing business, which could negatively impact demand for our frac sand products. In addition, heightened political, regulatory
and public scrutiny of hydraulic fracturing practices could potentially expose us or our customers to increased legal and regulatory proceedings, and any such
proceedings could be time-consuming, costly or result in substantial legal liability or significant reputational harm. Any such developments could have a
material adverse effect on our business, financial condition and results of operations, whether directly or indirectly.

If we or our customers are not able to obtain and maintain necessary permits, our results of operations could suffer.

We hold numerous governmental, environmental, mining and other permits and approvals authorizing operations at each of our facilities. Our future
success depends on, among other things, our ability, and the ability of our customers, to obtain and maintain the necessary permits and licenses required to
conduct operations. In order to obtain permits and renewals of permits in the future, we may be required to prepare and present data to governmental authorities
pertaining to the impact that any proposed exploration or production activities may have on the environment. Compliance with these regulatory requirements is
expensive and significantly lengthens the time needed to conduct operations. Additionally, obtaining or renewing required permits is sometimes delayed,
conditioned or prevented due to community opposition, opposition from other parties, the location of existing or proposed third-party operations, or other
factors beyond our control. The denial of a new or renewed permit essential to our operations, delays in the environmental review and permitting process,
significant opposition to a permit by third parties or the imposition of conditions in order to acquire the permit could impair our ability to continue operations at
the affected facilities, delay those operations, or involve significant unplanned costs, any of which could adversely affect our business, financial condition and
results of operations.

We are subject to regulations that impose stringent health and safety standards on numerous aspects of our operations.

Multiple aspects of our operations are subject to health and safety standards, including our mining operations, our trucking operations, and employee

exposure to crystalline silica.

Our mining operations are subject to the Mine Act, as amended by the Mine Improvement and New Emergency Response Act of 2006, which imposes

stringent health and safety standards on numerous aspects of mineral extraction and processing operations, including the training of personnel, operating
procedures, operating equipment and other matters. Our operating locations are regularly inspected by the MSHA for compliance with the Mine Act.

The DOT and various state agencies exercise broad powers over our trucking services, generally governing matters including authorization to engage in

motor carrier service, equipment operation, safety, and financial reporting. In addition, our operations must comply with the Fair Labor Standard Act, which
governs such matters as wages and overtime, and which is administered by the Department of Labor (“DOL”). We may be audited periodically by the DOT or
the DOL to ensure that we are in compliance with these safety, hours-of-service, wage and other rules and regulations.

We are also subject to laws and regulations relating to human exposure to crystalline silica. Several federal and state regulatory authorities, including

MSHA and OSHA, may continue to propose changes to their regulations regarding workplace exposure to crystalline silica, such as permissible exposure
limits, required controls and personal protective equipment. Our failure to comply with existing or new health and safety standards, or changes in such
standards or the interpretation or

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enforcement thereof, could require us or our customers to modify operations or equipment, shut down some or all operating locations, impose significant
restrictions on our ability to conduct operations or otherwise have a material adverse effect on our business, financial condition and results of operations.

Silica-related health issues and litigation could have a material adverse effect on our business, reputation and results of operations.

The inhalation of respirable crystalline silica is associated with the lung disease silicosis. There is evidence of an association between crystalline silica

exposure or silicosis and lung cancer and possible association with other diseases, including immune system disorders such as scleroderma. These health risks
have been, and may continue to be, a significant issue confronting the commercial silica industry. Concerns over silicosis and other potential adverse health
effects, as well as concerns regarding potential liability from the use of silica, may have the effect of discouraging our customers’ use of our silica products. The
actual or perceived health risks of mining, processing and handling silica could materially and adversely affect silica producers, including us, through reduced
use of silica products, the threat of product liability or employee lawsuits, increased scrutiny by federal, state and local regulatory authorities of us and our
customers or reduced financing sources available to the commercial silica industry.

Since at least 1975, we and/or our predecessors have been named as a defendant, usually among many defendants, in numerous product liability lawsuits
brought by or on behalf of current or former employees of our customers alleging damages caused by silica exposure. Almost all of the claims pending against
us arise out of the alleged use of our silica products in foundries or as an abrasive blast media, involve various other defendants and have been filed in the States
of Texas, Louisiana and Mississippi, although some cases have been brought in many other jurisdictions over the years. For further information about material
pending proceedings, see Item 3. Legal Proceedings of this Annual Report on Form 10-K. The silica-related litigation brought against us to date and associated
litigation costs, settlements and verdicts have not resulted in a material liability to us to date, and we presently maintain insurance policies where available.
However, we continue to have silica exposure claims filed against us, including claims that allege silica exposure for periods or in areas not covered by
insurance, and the costs, outcome and impact to us of any pending or future claims is not certain. Any such pending or future claims or inadequacies of our
insurance coverage could have a material adverse effect on our business, reputation, financial condition and results of operations.

Due to the international nature of parts of our business, we are subject to both U.S. and foreign regulations that could negatively impact our business.

In addition to U.S. laws and regulations, we are also subject to regulation in non-U.S. jurisdictions in which we conduct business, including with respect

to environmental, employee and other matters. The requirements for compliance with these laws and regulations may be unclear or indeterminate and may
involve significant costs, including additional capital expenditures or increased operating expenses, or require changes in business practice, in each case that
could result in reduced profitability for our business. Our need to comply with these foreign laws and regulations may provide an advantage to competitors who
are not subject to comparable restrictions or may restrict our ability to take advantage of growth opportunities. In addition, because the laws and regulations in
different jurisdictions can vary substantially, we may be required to undertake different steps or otherwise experience increased costs or other challenges in
order to comply with the laws and regulations in each of the multiple jurisdictions in which we operate.

In addition, the United States regulates our international operations through various statutes, including the U.S. Foreign Corrupt Practices Act (“FCPA”).

The FCPA and similar anti-bribery laws in other jurisdictions generally prohibit U.S.-based companies and their intermediaries from making improper
payments to non-U.S. officials for the purpose of obtaining or retaining business. We operate in parts of the world that experience government corruption to
some degree, and, in certain circumstances, compliance with anti-corruption laws may conflict with local customs and practices. Although we maintain policies,
procedures and controls and deliver training designed to ensure compliance with anti-corruption laws, such efforts may not be sufficient to protect us from
liability under these laws.

If we are found to be liable for regulatory violations related to our international operations, we could suffer from criminal or civil penalties or other

sanctions, any of which could have a material adverse effect on our business, financial condition, and results of operations.

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Strategic & General Business Risks

We must effectively manage our production capacity so that we can appropriately react to fluctuations in demand for our products.

To meet rapidly changing demand in the markets we serve, we must effectively manage our resources and production capacity. During periods of
decreasing demand we must be able to appropriately align our cost structure with prevailing market conditions and effectively manage our mining operations.
Our ability to rapidly and effectively reduce our cost structure in response to such downturns is limited by the fixed nature of many of our expenses in the near
term and by our need to continue to invest in maintaining reserves and production capabilities. Conversely, when upturns occur in the markets we serve, we
may have difficulty rapidly and effectively increasing our production capacity or incur substantial costs related to restarting idled facilities or executing other
expansion plans. A failure to timely and appropriately adapt our resources, costs and production capacity to changes in our business environment could have a
material adverse effect on our business, financial condition, and results of operations.

If we cannot successfully complete acquisitions or integrate acquired businesses, our growth may be limited, and our financial condition may be

adversely affected.

Our business strategy includes supplementing internal growth by pursuing acquisitions of complementary businesses. Any acquisition involves potential

risks, including, among other things:

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the validity of our assumptions about mineral reserves, future production, sales, capital expenditures, operating expenses and costs, including
synergies;
an inability to successfully integrate the businesses we acquire;
the use of a significant portion of our available cash or borrowing capacity to finance acquisitions and the subsequent decrease in our liquidity, or the
use of equity securities to fund an acquisition and the resulting dilution to our existing stockholders;
a significant increase in our interest expense or financial leverage if we incur additional debt to finance acquisitions;
the assumption of unknown liabilities, losses or costs for which we are not indemnified or for which our indemnity is inadequate;
the diversion of management’s attention from other business concerns;
an inability to hire, train or retain qualified personnel to manage and operate any growth in our business and assets;
the incurrence of other significant charges, such as impairment of goodwill or other intangible assets, asset devaluation or restructuring charges;
unforeseen difficulties encountered in operating in new geographic areas or other new markets;
customer or key employee losses at the acquired businesses; and
the accuracy of data obtained from production reports and engineering studies, geophysical and geological analyses and other information used when
deciding to acquire a property, the results of which are often inconclusive and subject to various interpretations.

We may need to recognize impairment charges related to goodwill, identifiable intangible assets, and fixed assets, in which case our net earnings and

net worth could be materially adversely affected.

Under the acquisition method of accounting, net assets acquired are recorded at fair value as of the acquisition date, with any excess purchase price

allocated to goodwill. Our acquisitions have resulted in significant balances of goodwill and identifiable intangible assets. There is significant judgment
required in the analysis of a potential impairment of goodwill, identified intangible assets and fixed assets. If, as a result of a general economic slowdown,
deterioration in one or more of the markets in which we operate, impairment in our financial performance and/or future outlook or decline in our market
capitalization due to other factors, the estimated fair value of our long-lived assets or goodwill decreases, we may determine that one or more of our long-lived
assets or our goodwill is impaired. Any such impairment charge would be determined based on the estimated fair value of the assets and could have a material
adverse effect on our financial condition, and results of operations.

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Failure to protect our intellectual property rights may undermine our competitive position, and protecting our rights or defending against third-party

allegations of infringement may be costly.

Our commercial success depends on our proprietary information and technologies, know-how and other intellectual property. Because of the technical

nature of our business, we rely primarily on patents, trade secrets, trademarks and contractual restrictions to protect our intellectual property rights. The
measures we take to protect our patents, trade secrets and other intellectual property rights may be insufficient. In addition, certain non-U.S. jurisdictions where
we operate offer limited intellectual property protections relative to the United States. Failure to protect, monitor and control the use of our existing intellectual
property rights could cause us to lose our competitive advantage and incur significant expenses. It is possible that our competitors or others could independently
develop the same or similar technologies or otherwise obtain access to our unpatented technologies. In such case, our patents and trade secrets would not
prevent third parties from competing with us. Furthermore, third parties or employees may infringe or misappropriate our proprietary technologies or other
intellectual property rights. Policing unauthorized use of intellectual property rights can be difficult and expensive, and adequate remedies may not be available.

In addition, third parties may claim that our products infringe or otherwise violate their patents or other proprietary rights and seek corresponding
damages or injunctive relief. Defending ourselves against such claims, with or without merit, could be time-consuming and result in costly litigation. An
adverse outcome in any such litigation could subject us to significant liability to third parties (potentially including treble damages) or temporary or permanent
injunctions prohibiting the manufacture or sale of our products, the use of our technologies or the conduct of our business. Any adverse outcome could also
require us to seek licenses from third parties (which may not be available on acceptable terms, or at all) or to make substantial one-time or ongoing royalty
payments. Protracted litigation could also result in our customers or potential customers deferring or limiting their purchase or use of our products until
resolution of such litigation. In addition, we may not have insurance coverage in connection with such litigation and may have to bear all costs arising from any
such litigation to the extent we are unable to recover them from other parties. Any of these outcomes could have a material adverse effect on our business,
financial condition, and results of operations.

Capital Resources & Stock Ownership Risks

We will need substantial additional capital to maintain, develop and increase our asset base, and the inability to obtain needed capital or financing, on

satisfactory terms, or at all, whether due to restrictions in our Credit Agreement or otherwise, could have an adverse effect on our growth and profitability.

Our business plan requires a significant amount of capital expenditures to maintain and grow our production levels over the long term. Although we

currently use a significant amount of our cash reserves and cash generated from our operations to fund the maintenance and development of our existing
mineral reserves and our acquisitions of new mineral reserves, we may need to depend on external sources of capital to fund future capital expenditures if
commercial silica prices were to decline for an extended period of time, if the costs of our acquisition and development operations were to increase substantially
or if other events were to occur that reduce our sales or increase our costs. Our ability to obtain bank financing or to access the capital markets for future equity
or debt offerings may be limited by our financial condition at the time of any such financing or offering, adverse market conditions or other contingencies and
uncertainties that are beyond our control. Our failure to obtain the funds necessary to maintain, develop and increase our asset base could adversely impact our
growth and profitability.

In addition, our existing Credit Agreement contains, and any future financing agreements we may enter into could also contain, operating and financial

restrictions and covenants that may limit our ability to finance future operations or capital needs or to engage in, expand or pursue our business activities.

Our ability to comply with these restrictions and covenants is uncertain and will be affected by the levels of cash flow from our operations and events and
circumstances beyond our control. If market or other economic conditions deteriorate, our ability to comply with these covenants may be impaired. If we violate
any of the restrictions, covenants, ratios or tests in our Credit Agreement, a significant portion of our indebtedness may become immediately due and payable
and our lenders’ commitment to make further loans to us may terminate. We might not have, or be able to obtain, sufficient funds to make these accelerated
payments. In addition, our obligations under our Credit Agreement are secured by substantially all of our assets, and if we are unable to repay our indebtedness
or satisfy our other obligations under our Credit Agreement, the lenders could seek to foreclose on our assets.

Even if we are able to obtain financing or access the capital markets, incurring additional debt may significantly increase the risks associated with our

existing indebtedness, as discussed elsewhere in these risk factors. In addition, the issuance of

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additional common stock in an equity offering may result in significant stockholder dilution. Further, we may incur substantial costs in pursuing any capital-
raising transactions, including investment banking, legal and accounting fees, which may not be adequately offset by the proceeds from the transaction.

Our substantial indebtedness and pension obligations could adversely affect our financial flexibility and our competitive position.

We have, and we expect to maintain in the near term, a significant amount of indebtedness. On May 1, 2018, we entered into the Credit Agreement, which

consists of a $1.280 billion Term Loan and a $100 million Revolver that may also be used for swingline loans or letters of credit.

As of December 31, 2022, we had $1.059 billion of outstanding indebtedness under the Term Loan and we were using $21.5 million for outstanding letters

of credit, leaving $78.5 million of borrowing availability under the Revolver.

In response to increasing inflation, the U.S. Federal Reserve began to raise interest rates in March 2022. Prevailing high interest rates increase our cost of

capital. Additionally, borrowings under certain of our indebtedness are at variable rates of interest and expose us to interest rate volatility. If interest rates
increase, our debt service obligations on certain of our variable rate indebtedness will increase even though the amount borrowed remains the same.

In addition to our indebtedness, we also have, and will continue to have, significant pension obligations. The substantial level of these obligations

increases the risk that we may be unable to generate cash sufficient to pay amounts owed under these obligations when due. In such a case, we may be forced to
reduce or delay business activities, acquisitions, investments and/or capital expenditures; sell assets; restructure or refinance our indebtedness; or seek
additional equity capital or bankruptcy protection, and we may not be able to affect any of these remedies when necessary, on satisfactory terms or at all. Our
level of indebtedness and pension obligations could also have important consequences to you and significant effects on our business, including:

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increasing our vulnerability to adverse changes in general economic, industry and competitive conditions;
requiring us to dedicate a substantial portion of our cash flow from operations to make payments on our indebtedness and pension obligations, thereby
reducing the availability of our cash flow to fund working capital, capital expenditures and other general corporate purposes, including dividend
payments;
restricting us from exploiting business opportunities;
making it more difficult to satisfy our financial obligations, including payments on our indebtedness;
disadvantaging us when compared to our competitors that have less debt and pension obligations; and
increasing our borrowing costs or otherwise limiting our ability to borrow additional funds for the execution of our business strategy.

In addition, the amounts owed under the Credit Agreement use LIBOR as a benchmark for establishing the rate at which interest accrues. On March 15,

2022, President Biden signed the Consolidated Appropriation Act of 2022 into law, which includes the Adjustable Interest Rate (LIBOR) Act, containing
legislation related to the transition away from LIBOR. This legislation is intended to establish a uniform process for replacing LIBOR in existing contracts and
securities that continue after the cessation of LIBOR and do not contain clearly defined or practicable fallback provisions.

On July 19, 2022, the Federal Reserve Board released a proposal that provides default rules for certain contracts that use LIBOR, which would implement

the LIBOR Act with replacement rates based on the Secured Overnight Financing Rate (SOFR). We believe the LIBOR Act and the Federal Reserve Board's
proposed regulation help provide clarity for the transition of our legacy LIBOR contracts, including investment securities and loans, to alternative reference
rates in an orderly manner.

We may have to utilize significant cash to meet our unfunded pension obligations and post-retirement health care liabilities and these obligations are

subject to increase.

Many of our employees participate in our defined benefit pension plans. Declines in interest rates or the market values of the securities held by the plans

or other adverse changes could materially increase the underfunded status of our plans and affect the level and timing of required cash contributions. To the
extent we continue to use cash to reduce these unfunded liabilities, the amount of cash available for our working capital needs would be reduced. In addition,
under the Employee Retirement Income Security Act of 1974, as amended (“ERISA”), the Pension Benefit Guaranty Corporation (“PBGC”) has the authority
to institute proceedings to terminate a pension plan in certain circumstances. In the event our tax-qualified pension plans are terminated by the PBGC, we could
be liable to the PBGC for the underfunded amount, which could trigger default provisions in our Credit Agreement.

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We also have a post-retirement health and life insurance plan for many of our employees and former employees. The post-retirement benefit plan is

unfunded, and retiree health benefits are generally paid as covered expenses are incurred. We derive post-retirement benefit expense from an actuarial
calculation based on the provisions of the plan and a number of assumptions provided by us. Although we previously maintained a trust to partially fund health
care benefits for future retirees, the trust terminated in 2017 upon depletion of its assets in accordance with trust terms. As a result, our satisfaction of our
obligations under our post-retirement benefit plan increases our expenses and reduces our cash available for other uses.

See Note Q - Pension and Post-Retirement Benefits in our Consolidated Financial Statements included in Part II, Item 8. of this Annual Report on Form

10-K for more information about these plans.

Our stock price and trading volume has been and could continue to be volatile, and you may not be able to resell shares of your common stock when

desired, at or above the price you paid, or at all.

The stock market has experienced and continues to experience extreme price and volume fluctuations that have often been unrelated or disproportionate to

the operating performance of the underlying businesses. In 2022, our stock closed at a high of $20.99 per share and a low of $9.34 per share. Broad market
fluctuations may adversely affect the market price of our common stock, regardless of our actual operating performance. In addition to the other risks described
in this section, the market price of our common stock may fluctuate significantly in response to a number of factors, many of which we cannot control,
including inaccurate or unfavorable research or ratings published by industry analysts about our business, or a cessation of coverage of us by industry analysts;
quarterly variations in our operating results compared to market expectations; announcements by others in or affecting our industry or our customers; actions by
competitors; our acquisition of, investment in or disposition of other businesses; and other global or regional economic, political, legal and regulatory factors
that may not be directly related to our performance.

Volatility in the market price or trading volume of our common stock may make it difficult or impossible for you to sell your common stock at or above

the price at which you purchased the stock. As a result, you may suffer a loss on your investment. Securities class action litigation has often been instituted
against companies following periods of volatility in the overall market and in the market price of a company’s securities. This litigation, if instituted against us,
could result in substantial costs, reduce our profits, divert our management’s attention and resources and harm our business.

Holders of our common stock may not receive dividends on our common stock.

Holders of our common stock are entitled to receive only such dividends as our Board of Directors may declare out of funds legally available for such
payments. Our Board of Directors elected to suspend dividends after paying a dividend in March 2020, and we have yet to resume paying dividends. Applicable
Delaware law provides that we may pay dividends only out of a surplus, as determined under Delaware law, or, if there is no surplus, out of net profits for the
fiscal year in which the dividend was declared and for the preceding fiscal year if certain specified conditions are met. Any determination to pay dividends and
other distributions in cash, stock or property by us in the future will be at the discretion of our Board of Directors and will be dependent on then-existing
conditions, including business conditions, our financial condition, results of operations, liquidity, capital requirements, the ability of our subsidiaries to pay us
dividends or make other distributions to us, contractual restrictions (including restrictive covenants contained in the Credit Agreement or other debt agreements)
and any other factors our Board of Directors deems relevant. We are not required to declare future cash dividends on our common stock, and our Board of
Directors may determine not to do so at any time.

Anti-takeover provisions in our charter documents and Delaware law might discourage or delay acquisition attempts for us that you might consider

favorable.

Our certificate of incorporation and bylaws contain provisions that may make the acquisition of our company more difficult without the approval of our

Board of Directors. These provisions:

• authorize the issuance of undesignated preferred stock, the terms of which may be established and the shares of which may be issued without

stockholder approval, and which may include super voting, special approval, dividend, or other rights or preferences superior to the rights of our
common stock;

• prohibit stockholder action by written consent, which requires all stockholder actions to be taken at a meeting of our stockholders;
• provide that our Board of Directors is expressly authorized to make, alter or repeal our bylaws;
• establish advance notice requirements for nominations of directors or for proposing matters that can be acted upon by stockholders at stockholder

meetings; and

23

• prevent us from engaging in a business combination with a person who acquires at least 15% of our common stock for a period of three years from

the date such person acquired such common stock, unless Board or stockholder approval is obtained prior to the acquisition.

These anti-takeover provisions and other provisions under Delaware law could discourage, delay or prevent a transaction involving a change in control of

our company, even if doing so would benefit our stockholders. These provisions could also discourage proxy contests and make it more difficult for you and
other stockholders to elect directors of your choosing and to cause us to take other corporate actions you desire.

We are required to develop and maintain effective disclosure controls and procedures and any failure to maintain the adequacy of our disclosure

controls and procedures may adversely affect investor confidence and, as a result, the value of our shares of common stock.

Under Sarbanes-Oxley, we are required to assess the effectiveness of our disclosure controls and procedures on an annual basis. Solely as a result of the

changes we had to make to our mining disclosures in our Form 10-K for the fiscal year ended December 31, 2021, our Chief Executive Officer and Chief
Financial Officer concluded that our disclosure controls and procedures were not effective as of December 31, 2021. To remediate this conclusion, during 2022
we engaged a new qualified person to prepare our mining technical report studies and review the related mining disclosure. Because the omitted disclosures did
not affect our financial statements, no additional remediation was deemed necessary. As of result of the remediation, our Chief Executive Officer and Chief
Financial Officer concluded that our disclosure controls and procedures were effective as of December 31, 2022. If we fail to maintain effective disclosure
controls and procedures investor confidence could be negatively affected, which could have a material adverse impact on the market price of our common
stock.

Labor & Employment Risks

Our business may suffer if we are unable to attract and retain members of our workforce.

We depend to a large extent on the services of our senior management team and other key personnel. These employees have extensive experience and

expertise in evaluating and analyzing industrial mineral properties, maximizing production from such properties, marketing industrial mineral production and
developing and executing financing and hedging strategies.

Competition for management and key personnel is intense, and the pool of qualified candidates is limited. The loss of any of these individuals or the

failure to attract additional personnel as needed could have a material adverse effect on our operations and could lead to higher labor costs or the use of less-
qualified personnel. In addition, if any of our executives or other key employees were to join a competitor or form a competing company, we could lose
customers, suppliers, know-how and other personnel. Our operations also rely on skilled laborers using modern techniques and equipment to mine efficiently.
We may be unable to train or attract the necessary number of skilled laborers to maintain our operating costs.

With respect to our trucking services, the industry periodically experiences a shortage of qualified drivers, particularly during periods of economic
expansion, in which alternative employment opportunities are more plentiful and freight demand increases, or during periods of economic downturns, in which
unemployment benefits might be extended and financing is limited for independent contractors who seek to purchase equipment or for students who seek
financial aid for driving school. Our independent contractors are responsible for paying for their own equipment, fuel, and other operating costs, and significant
increases in these costs could cause them to seek higher compensation from us or seek other opportunities within or outside the trucking industry. The trucking
industry suffers from a high driver turnover rate, which requires us to continually recruit a substantial number of drivers to operate our equipment and could
negatively affect our operations and expenses if we are unable to do so. Our success will be dependent on our ability to continue to attract, employ and retain
highly skilled personnel at all levels of our operations.

Our profitability could be negatively affected if we fail to maintain satisfactory labor relations.

As of December 31, 2022, various labor unions represented approximately 28% of our hourly employees. If we are unable to renegotiate acceptable
collective bargaining agreements with these labor unions in the future, we could experience, among other things, strikes, work stoppages or other slowdowns by
our workers and increased operating costs as a result of higher wages, health care costs or benefits paid to our employees. An inability to maintain good
relations with our workforce could cause a material adverse effect on our business, financial condition, and results of operations.

24

ITEM 1B.

UNRESOLVED STAFF COMMENTS

None. 

25

ITEM 2.

PROPERTIES

Our Properties and Logistics Network

Our corporate headquarters is located in Katy, Texas. We also maintain a corporate support center and sales office in Reno, Nevada. Additionally, we
operate corporate laboratories located in Berkeley Springs, West Virginia and Reno, Nevada. These locations provide critical technical expertise, analytical
testing resources and application development to promote product value and cost savings. We generally own our principal production properties, although some
land is leased. Substantially all of our owned assets are pledged as security under the Credit Agreement; for additional information regarding our indebtedness
see Note K - Debt to our Consolidated Financial Statements in Part II, Item 8. of this Annual Report on Form 10-K. Corporate offices, including sales locations
are leased. In general, we consider our facilities, taken as a whole, to be suitable and adequate for our current operations.

We continue to strategically position our supply chain in order to deliver our products according to our customers' needs, whether at a plant, a transload,
or at the wellhead. We believe that our supply chain network and logistics capabilities are a competitive advantage that enables us to provide superior service
for our customers and positions us to take advantage of opportunistic spot market sales. As of December 31, 2022, we had 35 transload facilities strategically
located near all the major shale basins in the United States. All of our transloads are operated by third-party transload service providers via service agreements,
which include both longer term contracts (generally 2 to 5 years) and month-to-month arrangements.

We lease a significant number of railcars for shipping purposes and for short-term storage of our products, particularly our frac sand products. As of

December 31, 2022, we had a leased fleet of 5,777 railcars.

Our acquisition of SandBox extended our delivery capability directly to our customers' wellhead locations. SandBox provides last mile logistics to
companies in the oil and gas industry, which increases efficiency and provides a lower cost logistics solution for our customers. SandBox has operations in the
major United States oil and gas producing regions, including the Permian Basin, Eagle Ford Shale, Mid-Con, Rocky Mountains and the Marcellus/Utica Shale,
where its largest customers are located. We expect we will continue to make strategic investments and develop partnerships with transload operators and
transportation providers that will enhance our portfolio of supply chain services that we can provide to customers.

26

The map below shows the location of our mines, production facilities, transload facilities, SandBox operation sites and Corporate offices:

Summary Overview of Mining Operations

Information concerning our material mining properties in this Annual Report on Form 10-K has been prepared in accordance with the requirements of

subpart 1300 of Regulation S-K, which first became applicable to us for the fiscal year ended December 31, 2021. As used in this Annual Report on Form 10-
K, the terms "mineral resource", "mineral reserve", "proven mineral reserve" and "probable mineral reserve" are defined and used in accordance with subpart
1300 of Regulation S-K. As of December 31, 2022, our individually material mining properties, as determined in accordance with subpart 1300 of Regulation
S-K, were the Crane, TX site (the "Crane site"), Lamesa, TX site (the "Lamesa site"), the Ottawa, IL site (the "Ottawa site") and the Lovelock/Colado, NV site
(the "Colado site").

The information that follows related to the Crane site, the Lamesa site, the Ottawa site and the Colado site is derived, for the most part from, and in some

instances is an extract from, the technical report summaries ("TRSs") related to such properties prepared in compliance with the Item 601(b)(96) and subpart
1300 of Regulation S-K. Portions of the following information are based on assumptions, qualifications and procedures that are not fully described herein.
Reference should be made to the full text of the TRSs, filed as exhibits to this Annual Report on 10-K.

As of December 31, 2022, we had 27 operating mines and processing facilities and two additional exploration stage properties, as summarized below.
Note that this list includes two processing facilities (Blair, NE and Millen, GA), but excludes mines and processing facilities that have been closed or idled,
none of which have any current economic reserves.

27

 
Berkeley Springs, West Virginia

We, through U.S. Silica Company, operate surface mines and a silica sand processing plant in Berkeley Springs, Morgan County, West Virginia. The Berkeley
Springs site includes a total of 4,435 acres that are owned outright by U.S. Silica. This ownership includes subsurface mineral and water rights. The site has no
leased property and pays no royalties.

Our surface mines at the Berkeley Springs facility use hard rock mining methods to produce high-purity sandstone. The plant uses natural gas, propane, fuel oil
and electricity to make whole grain, ground and fine ground silica. Berkeley Springs also produces a synthetic magnesium-silica product called Florisil. The
reserves are part of the Ridgeley Sandstone Formation along the Warm Springs Ridge in eastern West Virginia. The processing plant allows the Berkeley
Springs facility to meet a wide variety of focused specifications from customers producing specialty epoxies, resins and polymers, geothermal energy
equipment and fiberglass. As such, the Berkeley Springs facility services multiple end markets, such as glass, building products, foundry, chemicals and fillers
and extenders.

Berkeley Springs operates under 13 different operating permits and complies with other state and federal regulations that do not require a specific permit. All
required permits are secured, and the site is operating in full compliance.

Blair, Nebraska [processing plant only]

EPM operates a perlite processing plant located near the town of Blair, Washington County, Nebraska. The site sits on a 6.6-acre leased parcel that is a portion
of a 25.2-acre lot owned by Blair Ag., LLC. The site has a mobile office, expander building, a compressor room and three storage silos.

Our Blair facility uses natural gas, electricity and perlite raw ore from our open-pit Popcorn, Nevada mine that has been initially processed at our Lovelock,
Nevada process facility, then shipped by rail to Blair. After unloading, the ore goes through an expander. At temperatures over 1,600-degrees Fahrenheit, perlite
expands to almost 15 times its size. The expanded perlite is then sized, packaged or sent to storage silos for bulk shipment to customers. Perlite products are
used as a filter media in the manufacturing of bio-fuels, food grade oils, beverages and pharmaceuticals.

The Blair plant operates under one operating permit and complies with other state and federal regulations that do not require a specific permit. The required
permit is secured, and the site is operating in full compliance.

Clark, Nevada

EPM operates the Clark, Nevada mine and DE processing plant located 20 miles east of the city of Reno, Nevada. The Clark processing plant is located on
approximately 447 acres of private land. The Clark mine consists of approximately 1,123 acres of private land and 292 acres of federal land. EPM maintains
two mineral claim leases, with EPM holding 71% ownership. The leases consist of 19 mineral claims, 15 of which are placer claims and four of which are
millsite claims.

Our Clark open pit, ramp and bench mine uses mechanical, hard-rock mining methods to extract the DE ore strata. The DE mined at the Clark mine is part
of the Miocene-aged Truckee Formation, comprised of up to 200-ft thick, lacustrine DE deposits with interbedded, gravels, sands and volcanic tuffs. The Clark
processing plant utilizes a rotary kiln to produce granular DE products utilized in the soil amendment, absorbent and carrier markets. In addition, a flash dryer
process is utilized in producing natural DE powders in support of the functional additive and natural insecticide and animal feed markets.

The Clark mine operates under four permits, while the Clark processing plant must abide by eight separate operating permits. The site also complies with

other state and federal regulations that do not require a specific permit. All required permits are secured, and the site is operating in full compliance.

Columbia, South Carolina

We, through U.S. Silica Company, operate a surface mine and silica sand processing plant in Columbia, Lexington County, South Carolina. The processing
plant is situated on a 193-acre parcel of owned land. The active mine is located directly north of the plant and is comprised of a 733-acre parcel of leased land.
Royalties in the amount of 5% of the total monthly sales revenue are paid to the lessor.

Our surface mines in Columbia use natural gas, fuel oil and electricity to produce whole grain, ground and fine ground silica. The reserves are part of the
Tuscaloosa Formation in central South Carolina. The processing plant allows the Columbia facility to meet a wide variety of focused specifications on product
composition from customers. As such, the Columbia facility services multiple end markets, such as glass, building products, fillers and extenders, and filtration.

28

 
 
 
 
The Columbia, South Carolina site actively maintains five regulatory and operating permits. The facility also complies with other state and federal

regulations that do not require a specific permit. All required permits are secured, and the site is operating in full compliance.

Crane, Texas

In accordance with subpart 1300 of Regulation S-K, we have determined that the Crane site is a material mining property. Therefore, a description of the

Crane site and its operations can be found below. See “— Crane, TX.”

Dubberly, Louisiana

We, through U.S. Silica Company, operate a surface dredge mine and a silica sand processing plant near Dubberly, Louisiana. The land holdings include a
total of 356 acres that are owned outright by the Company. The site pays an annual $200 royalty to the former land owner. Another 20 acres of land is leased for
$8,500 per year to provide access to the site’s National Pollutant Discharge Elimination System water discharge point. The owned and leased tracts include
subsurface mineral and water rights.

Our surface mines in Dubberly use natural gas and electricity to produce whole grain silica through dredge mining. The reserves are part of the Sparta

Formation. The processing plant allows the Dubberly facility to meet a wide variety of focused specifications on product composition from customers. As such,
the Dubberly facility services multiple end markets, such as glass, foundry and building products.

Dubberly maintains four operating permits. The site also complies with other state and federal regulations that do not require a specific permit. All required

permits are secured, and the site is operating in full compliance.

Fernley, Nevada

EPM owns and operates a surface mine and DE processing plant near the town of Fernley, Nevada. The processing plant is located on a 39.9 acre parcel of
private land. The Fernley mine property is comprised of 5,668 acres, which mostly consists of federal BLM land (142 active and owned placer mineral claims)
and 72.2 acres of private land. Portions of the private land are surface rights only, and related minerals rights are sub-leased from private land owners. There are
no royalties associated with the private land holdings at Fernley. BLM land lease payments are around $23,000 annually.

Our Fernley facility surface-mines DE and has a rotary kiln for granular DE products. The processing plant utilizes electricity and recycled oil to

manufacture granular products used in absorbent products, soil amendments, fertilizer and pet litter.

The Fernley mine operates under four operating permits. The Fernley processing plant operates under an additional six operating permits. The site also

complies with other state and federal regulations that do not require a specific permit. All required permits are secured, and the site is operating in full
compliance.

Festus, Missouri

We, through U.S. Silica Company, lease and have mineral rights for silica sand on 635 acres covering a limestone quarry that is owned and operated by Fred
Weber, Inc. (“Fred Weber”). The processing plant was constructed on a 40-acre tract within this lease. Fred Weber mines a layer of sandstone in the quarry and
delivers it to the processing plant on a price per ton basis. Any and all property ownership, leases and environmental permits related to the mine are the
responsibility of Fred Weber.

The Festus facility uses natural gas and electricity to produce whole grain silica from a sandstone reserve that we lease, subject to the lease’s expiration on
June 30, 2048. The ore is mined by a contractor using both surface and underground hard-rock mining methods. The reserves are part of the St. Peter Sandstone
Formation that stretches north-south from Minnesota to Missouri and east-west from Illinois to Nebraska and South Dakota. While the Festus facility's
production techniques and distribution model enable it to serve all major silica markets, the primary production has been frac sand for oil and gas proppants.

Fred Weber holds and maintains six operating permits. The site also complies with other state and federal regulations that do not require a specific permit.

All required permits are secured, and the site is operating in full compliance.

Hazen Mine, Nevada

EPM operates the Hazen, Nevada DE mine that is located three miles southwest of the unincorporated town of Hazen, Churchill County, Nevada. The

Hazen mine is located on approximately 1,255 acres of land, comprised of 120 acres of private land and 1,135 acres of federal BLM land. The BLM land is held
by four different claim holders. The largest 640-acre parcel has an annual minimum payment of $24,000 and a $1/ton shipped royalty. The second 480-acre
parcel has an annual minimum

29

 
 
 
 
 
 
 
 
 
 
 
payment of $7,200 and a $1/ton shipped royalty. The next 13.5-acre parcel has a $1,650 annual payment and a $1/ton shipped royalty. The last 1.7-acre property
has a fixed annual payment of $413. Additionally, EPM pays all of the annual mining claim fees at $165 per claim.

Our small open-pit surface mine at Hazen operates as a stand-alone, satellite mine that provides raw DE to several sites. Most of the raw ore is shipped by
truck to the Company’s nearby DE processing plant at Clark, Nevada. To a lesser extent, raw ore is loaded and shipped by rail to Johns Manville’s processing
plants in Fruita, Colorado and Grambling, Louisiana. Contracted mining campaigns take place every two to three years and these are designed to build on-site
stockpiles to meet shipping requirements. On average, 20,000 bank cubic yards of DE are shipped off site each year.

The Hazen mine operates under five operating permits issued by federal and state agencies. The site also complies with other state and federal regulations

that do not require a specific permit. All required permits are secured, and the site is operating in full compliance.

Hurtsboro, Alabama

We, through U.S. Silica Company, operate a silica sand mine and processing plant near Hurtsboro, Macon County, Alabama. The Hurtsboro processing plant

is located on 117 acres of owned land. Mining occurs within 10 miles of the processing plant, on three separate leased land parcels that encompass a total of
some 1,100 acres. The mineral leases include subsurface mineral rights, with royalties paid at $0.60 to $0.75 per ton mined.

Our surface mines in Hurtsboro use propane and electricity to produce whole grain silica. The reserves are mined from the Cusseta member of the lower
Ripley Formation. The processing plant allows the Hurtsboro facility to meet a wide variety of focused specifications on product composition from customers.
As such, the Hurtsboro site services multiple end markets, such as foundry, building products and recreation.

The Hurtsboro site maintains 11 separate mining and environmental permits. The site also complies with other state and federal regulations that do not

require a specific permit. All required permits are secured, and the site is operating in full compliance.

Jackson/Aberdeen, Mississippi

EP Engineered Clays, our indirect subsidiary, operates a bentonite clay processing plant in the town of Jackson, Hinds County, Mississippi. The Jackson
processing facility sits on 70 acres of private land leased from BASF, the former owner of the site. The annual lease rate for the plant is $157,000. EPM also
owns a one-acre lot located next to the processing plant as an injection well site. The calcium bentonite raw ore supplied to the Jackson plant is mined at the
Aberdeen / Fowlkes Mine, near the town of Aberdeen, Monroe County, Mississippi. The mine property is 648 acres, comprised of 502 acres of owned land and
146 acres of private leased land, split between three landowners. The total annual lease payment for the private property is $12,000.

Our Jackson facility uses natural gas, electricity, water and sulfuric acid to process calcium bentonite from our Fowlkes open-pit mine, located

approximately 170 miles from the Jackson plant. Once the calcium bentonite is processed into finished product, the product is shipped to the animal feed, oleo
bleaching/filtration or refinery catalyst/purification markets.

The Jackson plant operates under five separate operating permits. The Fowlkes Mine operates under two operating permits. Both sites also comply with

other state and federal regulations that do not require a specific permit. All required permits are secured, and the sites are operating in full compliance.

Jackson, Tennessee

We, through U.S. Silica Company, operate a silica sand mine and processing plant near Jackson, Tennessee. The Jackson, Tennessee site includes 132 acres

of owned land in two separate parcels. The processing plant is located on the smaller 27-acre parcel of owned land. The second parcel of 105 acres hosts a
mined-out dredge pond. There are no leases, no royalties and no other associated payments specific to the Jackson, Tennessee land parcels.

Our surface mines in Jackson, Tennessee use natural gas and electricity to produce whole grain and ground silica. Sand is purchased from a local dredging
company whose reserves are alluvial sands associated with an ancient river system. The processing plant allows the Jackson, Tennessee facility to meet a wide
variety of focused specifications on product composition from customers. As such, the site services multiple end markets, such as fiberglass, building products,
ceramics, fillers and extenders and recreation.

The Jackson, Tennessee site operates under three active permits. The site also complies with other state and federal regulations that do not require a specific

permit. All required permits are secured, and the site is operating in full compliance.

30

 
 
 
 
 
 
 
 
 
 
 
 
Lamesa, Texas

In accordance with subpart 1300 of Regulation S-K, we have determined that the Lamesa site is a material mining property. Therefore, a description of the

Lamesa site and its operations can be found below. See “— Lamesa, TX.”

Lovelock/Colado, Nevada

In accordance with subpart 1300 of Regulation S-K, we have determined that the Colado site, which includes the Lovelock Processing Plant, in Lovelock,

Nevada, is a material mining property. Therefore, a description of the Colado site and its operations can be found below. See “— Lovelock/Colado, NV.”

Mapleton Depot, Pennsylvania

We, through U.S. Silica Company, operate surface mines and a silica sand processing plant near Mapleton Depot, Huntingdon County, Pennsylvania. The
Mapleton Depot operation includes a total of 1,838 acres that are owned outright by U.S. Silica. This ownership includes subsurface mineral and water rights.
An additional 345 acres of land is leased for mineral rights and access from three different land owners. The standard lease payment is $0.255 per ore ton mined
on 260 acres of the lease land total. The remaining 85 acres have an annual lease amount of $98,000 for mine haulage route access.

Our surface mines in Mapleton Depot use natural gas, fuel oil and electricity to produce whole grain silica through hard rock mining. The reserves are part
of the Ridgeley (sometimes called the Oriskany) Sandstone Formation in central Pennsylvania. The processing plant allows the Mapleton Depot facility to meet
a wide variety of focused specifications on product composition from customers. As such, the Mapleton Depot site services multiple end markets, such as glass,
specialty glass, building products, recreation and oil and gas proppants.

Mapleton Depot operates under 21 different operating permits. The site also complies with other state and federal regulations that do not require a specific

permit. All required permits are secured, and the site is operating in full compliance.

Mauricetown, New Jersey

We, through U.S. Silica Company, own and operate a silica sand processing plant near the unincorporated community of Mauricetown, Cumberland County,
New Jersey. The processing plant is located on the west side of Mauricetown and sits on 488 owned acres of private land. The dredge mining operation, almost
six miles northeast near Port Elizabeth, is located on 816 acres of owned land. All property at both sites is owned outright by U.S. Silica. No royalties are paid
for the mining of sand on the property.

Our surface mines near the Mauricetown facility use natural gas, fuel oil and electricity to produce whole grain silica through dredge mining. The reserves
are mined from alluvial sands in the Maurice River Valley and are similar to those found in the Cohansey, Bridgeton and Cape May deposits. The processing
plant allows the Mauricetown facility to meet a wide variety of focused specifications on product composition from customers. As such, the Mauricetown site
services multiple end markets, such as foundry, filtration, building products and recreation.

Mauricetown operates under 25 separate permits. The site also complies with other state and federal regulations that do not require a specific permit. All

required permits are secured, and the site is operating in full compliance.

Middleton, Tennessee

EPM owns and operates the Middleton, Tennessee site, comprised of some 1,154 acres located on both sides of the border between Tennessee and

Mississippi. The bentonite clay processing plant sits on an owned, 131-acre parcel of land located five miles south of the town of Middleton, Hardeman County,
Tennessee. The Tennessee mines consist of 420 acres of owned land and 78 acres of leased land. Mining activities occur in both Tennessee and Mississippi. We
own all mineral rights on the leased land, but the land will be transferred back to the owner after cessation of mining. There is no royalty or other fee associated
with this lease. The Mississippi mines consist of 525 acres of owned land.

The Middleton facility surface-mines montmorillonite clay, a high calcium bentonite, and has two rotary kilns that have a capacity of roughly 150,000 tons

per year. The facility uses natural gas, electricity and sulfuric acid to process ore. With on-site milling, screening and multiple packaging capabilities, the
Middleton site serves several different industries including agriculture, sports fields and absorbents.

The Middleton mine operates under five separate operating permits. The Middleton processing plant operates under two additional state permits. The site

also complies with other state and federal regulations that do not require a specific permit. All required permits are secured, and the site is operating in full
compliance.

31

 
 
 
 
 
 
 
 
 
 
 
Mill Creek, Oklahoma

We, through U.S. Silica Company, own and operate the Mill Creek mine and processing plant, near the town of Mill Creek, Johnston County, Oklahoma.
The Mill Creek operation consists of two silica sand processing plants separated by four miles. The South Plant sits on 369 owned acres and is the home to the
ground silica milling, sizing and bagging operations. The North Plant is comprised of 1,501 owned acres and is home to the mine and the whole grain silica
sand drying and shipping operations. There are two leased tracts at the North Plant totaling 71 acres; both tracts have been fully mined, but the acreage is still
part of the active state mining permit. The purchase agreements for lands at the North Plant included provisions for royalty payments based on tons mined and
sold from the individual tracts. Some of this property was purchased over 40 years ago, and the royalty rates are less than the $0.10 per ton.

Our surface mines in Mill Creek use natural gas and electricity to produce whole grain, ground and fine ground silica through hydraulic mining. The

reserves are part of the Oil Creek Formation in south central Oklahoma. The processing plant enables the site to produce multiple whole grain and ground silica
products through various methods. As such, the Mill Creek facility services multiple end markets, such as glass, foundry, fillers and extenders, building
products and oil and gas proppants.

The North Plant and mine operate under eight separate operating permits. The South Plant must abide by six separate operating permits. The site also
complies with other state and federal regulations that do not require a specific permit. All required permits are secured, and both sites are operating in full
compliance.

Millen, Georgia [processing plant only]

We, through U.S. Silica Company, operate a silica processing facility located near the town of Millen, Jenkins County, Georgia. The site sits on 819 leased

acres, of which the processing plant covers approximately 50 acres.

Our Millen facility has a natural gas kiln that enables the production of specialty industrial products that require high temperature heat treatments. These
products are sold to customers that produce finished goods for the building products and residential construction markets. The site can ship bulk or packaged
material via truck and the Norfolk Southern railway.

There is only one operating permit of record for the Millen, Georgia Plant. The site also complies with other state and federal regulations that do not require

a specific permit. The required permit is secured, and the site is operating in full compliance.

Montpelier, Virginia

We, through U.S. Silica Company, own and operate an aplite mine and processing plant near the unincorporated community of Montpelier, Hanover County,

Virginia. The mine and processing plant are located on 824 owned acres, with full mineral rights. No leases or royalties are associated with the property.

Our surface mines in Montpelier use fuel oil and electricity to produce aplite through hard rock mining. The reserves are part of an igneous rock complex
that is unique to this location. The processing plant allows the Montpelier facility to meet a wide variety of focused specifications on product composition from
customers. As such, the Montpelier site services multiple end markets, such as glass, building products and recreation.

The Montpelier site maintains four different operating permits. The site also complies with other state and federal regulations that do not require a specific

permit. All required permits are secured, and the site is operating in full compliance.

Ottawa, Illinois

In accordance with subpart 1300 of Regulation S-K, we have determined that the Ottawa site is a material mining property. Therefore, a description of the

Ottawa site and its operations can be found below. See “— Ottawa, IL.”

Pacific, Missouri

We, through U.S. Silica Company, own and operate a silica sand mine and production facility near the town of Pacific, St. Louis County, Missouri. The

mine and processing plant are located on 524 wholly owned acres, with full sub-surface mineral and water rights. No leases, royalties or other specific
payments are associated with the property.

Our surface mines at the Pacific facility use natural gas and electricity to produce whole grain, ground and fine ground silica through a variety of mining
methods, including hard rock and hydraulic mining. The reserves are part of the St. Peter Sandstone Formation that stretches north-south from Minnesota to
Missouri and east-west from Illinois to Nebraska and South Dakota. The processing plant allows the Pacific facility to meet a wide variety of focused
specifications on product composition from customers. As such, the Pacific site services multiple end markets, such as glass, foundry, fillers and extenders and
oil and gas proppants.

32

 
 
 
 
 
 
 
 
 
 
 
The Pacific site maintains nine different operating permits. The site also complies with other state and federal regulations that do not require a specific

permit. All required permits are secured, and the site is operating in full compliance.

Popcorn, Nevada

EPM operates a stand-alone, satellite perlite mine located 18 miles south of the town of Fallon, Churchill County, Nevada. The mine is located on 196 acres

of leased federal BLM land, and is comprised of 10 lode mineral claims. The mineral claims are renewed with the BLM on an annual basis at a cost of
$165/claim, with a total annual cost of $1,650.

There are no buildings or facilities on this mine site. The only equipment is an owned service front-end loader that is used to muck from blasted ore

stockpiles and to load over-the-road haul trucks. The mine operates seasonally (typically for only 30-days per year) in order to build ore stockpiles for shipping.
The average annual mine production from the Popcorn mine is around 10,000 stockpile cubic yards.

The raw perlite ore is trucked as needed throughout the year to the Lovelock processing plant, some 80 miles away. At the Lovelock processing plant, the

perlite ore is crushed, sized and passed through a flash dryer. At this point, it is either loaded into railcars for shipment to the Blair, Nebraska facility or it is
further processed at the Lovelock plant.

The Popcorn mine maintains three different operating permits. The site also complies with other state and federal regulations that do not require a specific

permit. All required permits are secured, and the site is operating in full compliance.

Rockwood, Michigan

We, through U.S. Silica Company, own and operate a silica sand production facility within the city of Rockwood, Wayne County, Michigan. The site is
comprised of two land parcels, totaling 872 wholly owned acres with full sub-surface mineral and water rights. One land parcel hosts the processing plant; the
other land parcel is a drill-proven, undeveloped future mining reserve. No leases, royalties or other specific payments are associated with the Rockwood
property.

Our Rockwood facility uses natural gas and electricity to produce whole grain silica. Rockwood's own surface mining reserves are part of the Sylvania
Formation and are notable for their low iron content, making them particularly valuable to customers producing specialty glass for architectural or alternative
energy applications. Currently, sandstone ore is purchased from a local construction material company from that company's surface mining operation. The
processing plant allows the Rockwood facility to meet a wide variety of focused specifications on product composition from customers. As such, the Rockwood
site services multiple end markets, such as glass, building products, oil and gas proppants and chemicals.

The Rockwood facility maintains five operating permits. The site also complies with other state and federal regulations that do not require a specific permit.

All required permits are secured, and the site is operating in full compliance.

Sanders, Arizona

EPM operates a calcium bentonite clay mine near the town of Sanders, Apache County, Arizona. There is no clay processing plant at Sanders, just an open
pit mine. The mine property consists of some 10,240 acres comprised of private lands leased from Newmont Realty Company. The lease is based on a royalty
structure, with an advanced annual royalty of $20,000 and a production royalty of $0.72/ton of dry clay or $1.01/ton of overburden sand (both of which are
deducted from the royalty advance). Sand from the site is sold to a third-party, Silica Services. The royalty unit values are annually adjusted based on the
Consumer Price Index (“CPI”). No additional fees are associated with the property as Silica Services manages transportation logistics and associated fees with
BLM and the Navajo Indian Nation.

Mine operations include two open pits, and a seasonal mechanized bench mining strategy is employed. Overburden waste is mined and removed to access
the bentonite clay ore horizon during the wet, winter months. The ore is typically mined and stockpiled in the dry summer periods so that the clay has minimal
interaction with water. Mining is completed by a third-party contractor.

Due to the Sanders mine’s location on tribal lands within the Navajo Indian Nation’s Reservation, there are no permits required from any regulatory
authority for mining. Regardless, our operation still abides by the requirements captured in the Company’s Corporate Environmental Management Plan.

33

 
 
 
 
 
 
 
 
 
 
 
Sequoya, Nevada [exploration property]

The Sequoya, Nevada property is an advanced greenfield DE exploration property in Churchill County, Nevada. It is strategically located along a major
highway only seven miles northwest of our Fernley, Nevada Plant and 34 miles southeast from our Lovelock, Nevada processing plant. The site is accessible by
exploration and gravel roads that connect back to the I-80 exit at Jessup. EPM owns 42 placer claims that cover 840 acres of public land. The mineral claims are
renewed with the BLM on an annual basis at a cost of $165/claim, with a total annual cost of $6,930.

There are no buildings or facilities on site, only a couple of open surface test pits where a bulk sample had been obtained for plant process testing.

The site is currently permitted only for exploration and is in full compliance. No operating permits are required since the site is not developed for operations.

Siskiyou, California [exploration property]

The Siskiyou, California site is a greenfield DE exploration property in Siskiyou County, California and it is located approximately 23 miles south of Klamath
Falls, Oregon. EPM controls 152 placer claims (146 owned, 6 leased) that cover some 2,240 acres of public land. The owned claims are renewed with the BLM
on an annual basis at a cost of $165/claim, with a total annual cost of $24,090. The leased claims are renewed annually at a cost of $7,920.

The property is comprised mostly of undeveloped, high-plains ranch lands with suitable access for exploration drilling provided by pre-existing ranch roads.
There are no buildings or facilities on this exploration property.

The site is currently permitted only for exploration and is in full compliance. No operating permits are required since the site is not developed for operations.

Sparta, Wisconsin

We, through U.S. Silica Company, own and operate a silica sand dredge mine and production facility within the town of Sparta, Monroe County, Wisconsin.

The site is comprised of 614 wholly owned acres, with full sub-surface mineral and water rights. No leases, royalties or other specific payments are associated
with the Sparta site.

Our facility at Sparta uses natural gas and electricity to produce whole grain silica products. The reserve geology is that of high purity alluvial sands, with
the primary erosional source being the Wonewoc Formation, known for its round, coarse grains and superior crush strength properties, which makes it an ideal
substrate for oil and gas proppants. We mine sand through dredging, where the sand is extracted from the ground with water without the use of any chemicals.
The sand is then transported as slurry via pipeline to the processing facility where it is sorted and dried in a no-emissions manner with vibratory screens that use
gravity and clean-burning natural gas dryers.

The Sparta site maintains seven operating permits. The site also complies with other state and federal regulations that do not require a specific permit. All

required permits are secured, and the site is operating in full compliance.

Vale, Oregon

EPM owns and operates a DE mine and processing plant near the town of Vale, Malheur County, Oregon. The processing plant is on 300 owned acres
located seven miles southwest of Vale. The Vale mine is located 50 miles southwest of Vale, near Juntura, Oregon. The mine consists of some 12,640 acres of
land that is a combination of private, state and federal lands. There are 1,680 acres of private land, 1,280 acres of Oregon state land, 8,080 acres (186 mineral
claims) of BLM land and 1,600 acres of land patented under the Stock Raising Homestead Act (“SRHA”) with private surface estate and federal mineral estate
(320 acres of which are owned by EPM). Annual lease and royalty payments are made to the Diatomite Products Company ($15,000 minimum plus $10.60/ton
sold), the State of Oregon ($10,000 minimum plus $3.16/ton sold) and the federal government of the United States ($165/claim fee). The royalty unit values are
adjusted annually based on the CPI.

Our Vale open pit, ramp and bench mine uses mechanical, hard-rock mining methods to extract the DE ore strata. The DE ore strata are part of the Miocene-

aged, Juntura Formation. At the processing plant, two kilns can produce calcined and flux-calcined DE for use as filter aids, functional additives and low iron
brewing grades of filter aids. It has an annual capacity of approximately 120,000 tons and uses DE ore from the open-pit Celatom mine, natural gas, electricity
and soda ash.

The Vale site maintains eight operating permits (four plant and four mine). The site also complies with other state and federal regulations that do not require

a specific permit. All required permits are secured, and the site is operating in full compliance.

34

 
 
 
 
 
Summary of Annual Production

The table below shows annual mined volumes (in thousands) at our mining properties for the fiscal years ended December 31, 2022, 2021 and 2020:

Mine / Location

Product Type

2022

Tons Mined
2021

2020

(2)

(4)

(3)

Berkeley Springs, WV
(1)
Blair, NE
Clark, NV
Columbia, SC
Crane, TX
Dubberly, LA
Fernley, NV
Festus, MO
Hazen, NV
Hurtsboro, AL
Jackson/Aberdeen, MS
Jackson, TN
Lamesa, TX
Lovelock/Colado, NV
Mapleton Depot, PA
Mauricetown, NJ
Middleton, TN
Mill Creek, OK
Millen, GA
Montpelier, VA
Ottawa, IL
Pacific, MO
Popcorn, NV
Rockwood, MI
Sanders, AZ
Sequoya, NV
Siskiyou, CA
(10)
Sparta, WI
Vale, OR
(1) 

(6)

(8)

(9)

(5)

(7)

Silica Sand
Perlite
Diatomaceous Earth
Silica Sand
Silica Sand
Silica Sand
Diatomaceous Earth
Silica Sand
Diatomaceous Earth
Silica Sand
Bentonite Clay
Silica Sand
Silica Sand
Diatomaceous Earth
Silica Sand
Silica Sand
Bentonite Clay
Silica Sand
Silica Sand
Aplite
Silica Sand
Silica Sand
Perlite
Silica Sand
Bentonite Clay
Diatomaceous Earth
Diatomaceous Earth
Silica Sand
Diatomaceous Earth

283 
— 
54 
377 
3,886 
132 
63 
1,468 
7 
196 
84 
— 
5,871 
175 
457 
113 
190 
1,898 
— 
245 
3,230 
951 
8 
— 
14 
— 
— 
1,232 
133 

301 
— 
63 
398 
3,263 
138 
67 
1,567 
9 
196 
84 
— 
4,692 
166 
308 
166 
198 
1,544 
— 
163 
2,967 
942 
— 
— 
14 
— 
— 
2,025 
117 

275 
— 
68 
346 
697 
106 
46 
1,290 
11 
125 
74 
— 
3,271 
151 
265 
155 
216 
1,235 
— 
196 
1,953 
922 
9 
— 
13 
— 
— 
— 
105 

(2) 

(3) 

(4) 

(5) 

(6) 

(7) 

(8) 

(9) 

Blair, NE is a perlite processing plant. There are no tons mined on site.
Mining occurs at the Aberdeen, MS mine. Jackson, MS is the location of the clay processing plant.
Jackson, TN purchases raw sand from a third party. There are no tons mined on site.
Mining occurs at the Colado, NV mine. Lovelock, NV is the location of the DE processing plant.
Millen, GA is a silica sand processing plant. There are no tons mined on site.
Popcorn, NV mining is campaigned every two to three years. Raw ore is processed at Blair, NE and/or Lovelock/Colado, NV processing plant.
Rockwood, MI purchases raw sand from a third party. There are no tons mined on site.
Sequoya, NV is an advanced greenfield exploration property. No mining except a small (~300 tons) bulk sample has been mined from this site.
Siskiyou, CA is a greenfield exploration property. To date, no tons have been mined on site.
Sparta, WI was idled in 2020.

(10) 

35

Summary of Resources and Reserves

In accordance with subpart 1300 of Regulation S-K, we engaged John T. Boyd Company ("JT Boyd") as the qualified person to prepare the TRS for the

disclosure of resources and reserves at our four material mining properties: Crane, TX, Lamesa, TX, Ottawa, IL and Lovelock/Colado, NV. The estimates of
measured, indicated and inferred resources and proven and probable reserves at our four material mining properties in this Annual Report on Form 10-K have
been prepared by JT Boyd and in accordance with the technical definitions established by the SEC under subpart 1300 of Regulation S-K.

Set forth in the tables below are our estimates (in thousands of tons) as of December 31, 2022 of (1) measured, indicated and inferred resources (exclusive

of proven and probable reserves), (2) proven and probable reserves and (3) saleable reserves.

The reference point for the resources is in situ or in-place material. The reference point for mineable reserves is recoverable tons after mining extraction

losses. The reference point for saleable reserves is finished goods available for sale after process plant losses.

Summary of Resources for the fiscal year ended December 31, 2022

(1)

Measured
Resources

Indicated Resources

Measured + Indicated
Resources

Inferred Resources

(2)

(4)

Silica Sand
United States
   Berkeley Springs, WA
   Columbia, SC
   Crane, TX
   Dubberly, LA
   Festus, MO
   Hurtsboro, AL
(3)
   Jackson, TN
   Lamesa, TX
   Mapleton Depot, PA
   Mauricetown, NJ
   Mill Creek, OK
   Millen, GA
   Ottawa, IL
   Pacific, MO
   Rockwood, MI
   Sparta, WI
Total Silica Sand
Diatomaceous Earth
United States
   Clark, NV
   Fernley, NV
   Hazen, NV
   Lovelock/Colado, NV
   Sequoya, NV
   Siskiyou, CA
   Vale, OR
Total Diatomaceous Earth
Bentonite Clay
United States
   Jackson/Aberdeen, MS

(6)

(7)

(5)

— 
— 
— 
— 
— 
— 
— 
622 
— 
— 
— 
— 
— 
— 
— 
— 
622 

— 
— 
— 
— 
— 
— 
— 
— 

— 

— 
— 
2,246 
— 
— 
— 
— 
4,748 
— 
— 
— 
— 
— 
— 
— 
— 
6,994 

— 
— 
— 
— 
— 
— 
— 
— 

— 

36

— 
— 
2,246 
— 
— 
— 
— 
5,370 
— 
— 
— 
— 
— 
— 
— 
— 
7,616 

— 
— 
— 
— 
— 
— 
— 
— 

— 

7,950 
3,666 
16,396 
1,959 
— 
— 
— 
5,002 
— 
4,000 
16,361 
— 
88 
— 
— 
13,500 
68,922 

1,258 
4,727 
— 
689 
1,978 
3,656 
19,780 
32,088 

— 

(7)

— 
— 
— 

— 
— 
— 

— 
— 
— 

   Middleton, TN
   Sanders, AZ
Total Bentonite Clay
Perlite
United States
(8)
   Blair, NE
   Popcorn, NV
Total Perlite
(7)
Aplite
United States
   Montpelier, VA
Total Aplite
(1)
no resources reported represent a 100% conversion of currently known geologic resources to mineable reserves.
(2)

— 
— 
 Item 1303(b)(ii) of Regulation S-K requires disclosure of resources to be exclusive of reserves. Unless otherwise noted, properties with

11,806 
— 
11,806 

— 
— 
— 

— 
— 
— 

— 
— 
— 

— 
— 
— 

— 
— 

— 
— 

— 
— 

 Silica sand resources are based on the 2022 average price of $43 per ton.
 Jackson, TN purchases raw sand from a third party. There are no resources on this site.
 Millen, GA is a silica sand processing plant that receives ore from other sites. There are no resources on this site.
 Rockwood, MI purchases raw sand from a third party. There are no resources on this site.
 Diatomaceous earth resources are based on the 2022 average price of $675 per ton.
 Resources are based on the 2022 average price of $286 per ton of bentonite clay, perlite and aplite.
 Blair, NE is a perlite processing plant. There are no resources on this site.

(3)

(4)

(5)

(6)

(7)

(8)

Summary Reserves for the fiscal year ended December 31, 2022

Proven Reserves

(1)

Probable Reserves

(1)

Total Mineable
Reserves

(1)

Total Saleable
Reserves

(1)

(2)

(3)

Silica Sand
United States
   Berkeley Springs, WV
   Columbia, SC
   Crane, TX
   Dubberly, LA
   Festus, MO
   Hurtsboro, AL
(4)
   Jackson, TN
   Lamesa, TX
   Mapleton Depot, PA
   Mauricetown, NJ
   Mill Creek, OK
   Millen, GA
(7)
   Ottawa, IL
   Pacific, MO
   Rockwood, MI
   Sparta, WI
Total Silica Sand

(8)

(6)

(5)

— 
1,755 
37,632 
— 
7,411 
92 
— 
12,800 
2,100 
— 
— 
— 
1,486 
7,994 
— 
2,740 
74,010 

7,540 
8,638 
147,788 
3,818 
18,537 
585 
— 
106,111 
2,745 
10,969 
13,010 
— 
91,228 
17,479 
7,600 
20,250 
456,298 

6,484 
7,048 
121,925 
3,207 
13,903 
410 
— 
79,583 
2,471 
9,324 
11,839 
— 
78,913 
14,857 
4,940 
17,479 
372,383 

7,540 
6,883 
110,156 
3,818 
11,126 
493 
— 
93,311 
645 
10,969 
13,010 
— 
89,742 
9,485 
7,600 
17,510 
382,288 

37

(9)

(11)

(10)

(12)

Diatomaceous Earth
United States
   Clark, NV
   Fernley, NV
   Hazen, NV
   Lovelock/Colado, NV
   Sequoyah, NV
   Siskiyou, CA
   Vale, OR
Total Diatomaceous Earth
Bentonite Clay
United States
   Jackson/Aberdeen, MS
   Middleton, TN
   Sanders, AZ
Total Bentonite Clay
Perlite
United States
(13)
   Blair, NE
   Popcorn, NV
Total Perlite
Aplite
United States
   Montpelier, VA
Total Aplite
(1)
available for sale to customers.
(2) 

(12)

(12)

1,711 
1,085 
335 
1,671 
111 
— 
16,357 
21,270 

— 
2,513 
— 
2,513 

— 
4,323 
4,323 

— 
— 

1,745 
4,713 
84 
2,808 
755 
— 
27,287 
37,392 

1,063 
12,854 
570 
14,487 

— 
1,790 
1,790 

12,000 
12,000 

3,456 
5,798 
419 
4,479 
866 
— 
43,644 
58,662 

1,063 
15,367 
570 
17,000 

— 
6,113 
6,113 

— 
12,000 
12,000 

2,419 
4,679 
293 
3,655 
707 
— 
38,108 
49,861 

737 
6,608 
570 
7,915 

5,502 
5,502 

6,000 
6,000 

 Ore reserves are stated as "mineable" reserves (after mining losses) and saleable reserves (after processing plant losses) as finished product

Unless otherwise stated, silica sand reserves are based on the 2022 average price of $43 per ton.
Crane, TX economic evaluation based on $23.92/product ton; lower than 2022 ASP of $30.78/ product ton. No price escalation used.
 Jackson, TN purchases raw sand from a third party. There are no reserves or tons mined on site.
 Lamesa, TX economic evaluation based on $23.90/product ton; lower than 2022 ASP of $31.39/product ton. No price escalation used.
 Millen, GA is a silica sand processing plant that receives ore from other U.S. Silica sites. There are no ore reserves or tons mined at this site.
 Ottawa, IL economic evaluation based on $42.37/product ton; equal to 2022 ASP. No price escalation used.
 Rockwood, MI purchases raw sand ore from a third party. Unmined, proven ore reserves are wholly owned.
 Unless otherwise stated, diatomaceous earth reserves are based on the 2022 average price of $675 per ton.
 Lovelock/Colado, NV economic evaluation based on $697.27/product ton; equal to 2022 ASP. No price escalation used.
 Siskiyou, CA is a greenfield exploration property. As such, there are no mineable reserves to report.
 Reserves are based on the 2022 average price of $286 per ton of bentonite clay, perlite and aplite.
 Blair, NE is a perlite processing plant. There are no reserves or tons mined at this site.

(3) 

(4)

(5)

(6)

(7)

(8)

(9)

(10)

(11)

(12)

(13)

38

MATERIAL SITE DESCRIPTIONS

Crane, Texas

The Crane site is a surface proppant sand mining and processing operation located 25 miles west of the City of Odessa in Crane County, Texas. The cities

of Lubbock and Dallas, Texas, are located approximately 147 miles northeast and 355 miles east, respectively, of the Crane Operation. Geographically, the
Crane Operation’s processing plant is located at approximately 31° 38' 58.34" N latitude and 102° 42' 2.52" W longitude.

39

40

The Crane site is comprised of approximately 3,200 acres of surface and mineral rights wholly owned by U.S. Silica. We purchased the Crane site in May

2017 from McKnight Natural Resources and Flying U Properties after completing an initial reconnaissance-level exploration drilling campaign. The purchase
agreement included a royalty of $1 per ton of finished sand sold to be paid to the former owners. U.S. Silica is the first landowner to mine proppant sand at this
location. Other than sparse agricultural activity and various oil and gas infrastructure, previous landowners have not developed the site.

The Crane site is supported by various utilities and transportation networks needed to allow processing and transportation of finished proppant sands.
Electricity is delivered through an above-ground network that terminates at a substation at the processing facility, and from there electricity is distributed via
several underground and above-ground powerlines. Initial makeup water for industrial use is obtained through a regional water gathering and transport system
for mining and oil and gas operators in west Texas. Potable water is delivered via water jugs and bottles. Natural gas is supplied via several underground
pipelines. Tailings from processing are disposed of in old mining pit impoundments. Transportation needs are met through a well-developed road network on
both paved and graded dirt roads. No local railheads are present.

We conducted two exploration campaigns on the Crane site. The 26 drill holes completed in and around the property were utilized to define the lateral

extent, thickness, particle size distribution, and mineralogy of the target sand deposit at the Crane site. The site is currently in production phase. Contractors are
employed to conduct surface mining on the Crane site. The target sand deposit is excavated using conventional truck and excavator methods. The sand does not
require drilling or blasting. Excavators and/or front-end loaders are used to load articulated haul trucks with disaggregated sand. The haul trucks deliver raw
sand material to stockpiles located near the processing facilities.

Mined material from the stockpile arrives at the Wet Processing Plant by truck, where it is screened and washed to remove vegetation, oversize (> 40-

mesh) and fine waste (<200-mesh) material. The remaining material is mixed with water to create a slurry that is passed through a series of desliming cyclones
and attrition scrubbers to remove clay and undersized (very fine) particles. The deslimed material is then processed through a series of hydrosizers, hydro-
cyclones, and vacuum filters to remove excess water. The remaining “work-in-progress (WIP)” material is stockpiled outside on a drain pad to further reduce
moisture before it is recovered and enters the Dry Processing Plant. Within the Dry Processing Plant, the WIP sand is dried, sized and sorted. The 40/70-mesh
and 100-mesh dry finished products are stored in silos prior to loading in bulk truck for shipment to customers in the Permian Basin.

The Crane, TX process facility was built in early 2018 with all new and state-of-the-art equipment. This five-year old equipment and facility
infrastructure have been responsibly operated and maintained with a rigorous preventive maintenance program which keeps the plant ready to respond to
customer demand. The total net book value of the Crane site's real property and fixed assets as of December 31, 2022 was $173.8 million.

Several natural and man-made features have been identified in and around the Crane site which may limit the mineable areas of the property. These
features include setbacks from neighboring properties, setbacks from oil production infrastructure and setbacks from existing utility corridors. We have included
suitable setbacks in our mining plans to avoid disturbing these areas.

Mining and processing activities on the Crane site are regulated by several federal and state laws. As mandated by these laws and regulations, numerous

permits are required for mining, processing, and other incidental activities. All necessary permits are in place or applied for to support immediate operations.

A summary of Crane’s mineral resources and reserves as of December 31, 2022 and 2021 is shown below (in thousands of tons). For more information

on our resources and reserves, please refer to Sections 11.0 and 12.0 of the Crane TRS.

41

Crane, TX - Summary of Resources

Classification

Amount 

(1)(2)(3)

Amount 

(1)(2)

Amount Change
2022 vs. 2021

Percent Change 2022
vs. 2021

December 31, 2022 December 31, 2021

Measured
Indicated

— 
2,246 
2,246 

— 
— 
— 

— 
2,246 
2,246 

— 
100 %
100 %

16,396 
Item 1304(b)(2)(d)(2) of regulation S-K requires disclosure of resources to be exclusive of reserves. Unless otherwise noted, line items with no

    Total Measured + Indicated Resources
Inferred
(1) 
resources represent a 100% conversion of currently known geologic resources to mineable reserves.
(2)
production can be modified in response to that demand. As such, the application of minimum mining thicknesses, maximum stripping ratios, or cut-
off grades is not generally considered in the estimation of silica sand resources for the Crane site.
(3)

 Only one commodity (silica sand) is mined, processed and sold at the Crane site. Production of silica sand is driven by market demand. Silica sand

(10,904)

27,300 

 Mineral resources for Crane, TX are based on ASP of $30.78/product ton.

(40)%

Crane, TX - Summary of Reserves

December 31, 2022 December 31, 2021

Amount Change
2022 vs. 2021

Percent Change 2022 vs.
2021

(1)

(2)(4)

(2)(3)(4)

Amount

Amount

(6,252)
(5)
N/A

37,632 
31,046 

110,156 
90,879 

116,408 
(5)
N/A

Classification
Proven Reserves
Mineable
(5)
Saleable
Probable Reserves
Mineable
(5)
Saleable
Total Reserves
Mineable Total
(5)
Saleable Total
(1)
for sale to customers. Crane's mine recovery rate is 95% and process recovery rate is 82.5%, resulting in an overall product yield of 78.4%.
(2)
 Only one commodity (silica sand) is mined, processed and sold at the Crane site. Production of silica sand is driven by market demand. Silica sand
production can be modified in response to that demand. As such, the application of minimum mining thicknesses, maximum stripping ratios, or cut-off
grades is not generally considered in the estimation of silica sand reserves for the Crane site.
(3)

(10)%
(5)
N/A
 Ore reserves are stated as "mineable" reserves (after mining losses) and saleable reserves (after processing plant losses) as finished product available

 Crane, TX economic evaluation based on $23.92/product ton; lower than 2022 ASP of $30.78/product ton. No price escalation used.
 Based on the lateral geologic continuity of Crane's sand dune deposits, Proven ore is defined within 1/4-mile radius of a drill hole. Probable ore

(4)
extends out to 1/2-mile radius from a drill hole.
(5)
mineable reserves. In an effort to provide investors with a meaningful comparison during this period of transition, we have provided reserve estimates of
both the mineable and saleable tons for the fiscal year ended December 31, 2022. As the decision to report saleable reserves was not made until
December 31, 2022, saleable tons are not reported for the fiscal year ended December 31, 2021.

 On December 31, 2022, we determined to report our reserve estimates as saleable reserves. We have historically reported our reserve estimates as

163,908 
(5)
N/A

147,788 
121,925 

(16,120)
(5)
N/A

47,500 
(5)
N/A

(9,868)
(5)
N/A

(21)%
(5)
N/A

(5)%
(5)
N/A

The decrease in resources from 2021 to 2022 is primarily attributable to (1) geologic block model changes and (2) changes to the life of mine plan. The

decrease in reserves from 2021 to 2022 is primarily attributable to (1) depletion due to

42

mining of approximately 3,886,000 mineable tons, and (2) revisions to mine plans resulting in a downward adjustment of approximately 12,234,000 mineable
tons.

Key assumptions and parameters relating to the mineral reserves at the Crane site are discussed in Sections 11.0 and 12.0, respectively, of the Crane TRS.

Only material that can be economically, safely, and legally extracted is contained in these ore reserve estimates. Other key assumptions include the lateral
geologic continuity of the mineable dune sand ore strata, ore block model construction criteria, mine design elements (stable pit slope geometries, mining
bench height, pit floor limitations, pit dewatering, etc.), and setbacks (from property boundaries, power, natural gas, and water utility lines, oil well
infrastructure and ore quality).

Lamesa, Texas

The Lamesa site is a surface proppant sand mining and processing operation located 11 miles northwest of the town of Lamesa in Dawson County, Texas.

The cities of Dallas and Lubbock, Texas are located approximately 312 miles east and 56 miles northeast, respectively, of the Lamesa Operation.
Geographically, the Lamesa site's processing plant is located at approximately 32° 48' 22.522" N latitude and 102° 7' 33.823" W longitude.

43

44

The Lamesa site comprises approximately 3,523 acres of surface and minerals rights fully owned by U.S. Silica. We are the first owner to explore for and

mine proppant sand from the property. In developing the Lamesa Operation, we have completed three separate geologic exploration campaigns.

The site is accessible by private, state and county roads. The Lamesa site is connected to the local electrical and natural gas distribution systems. Lamesa

has four on-site water wells and contracts in place with third parties which cover the life of the mine and provide for adequate access to processing water. The
site has offices holding administrative, engineering, and operations staff. Additionally, there are several buildings that house the plant maintenance and support
facilities.

Contractors are employed to conduct surface mining on the central and western portions of the Lamesa property. The unconsolidated dune sands sit at the

surface, making it very amenable to open pit, mechanized mining methods utilizing heavy mobile mining equipment. At the mine, the unconsolidated sand is
extracted directly from the open pit wall / mining face by front-end loader or by excavator and loaded into 40-ton or 60-ton articulated haul trucks. A fleet of
haul trucks then delivers the mined sand ore to the processing plant.

At the processing plant, raw sand is sent through a static grizzly deck and vibratory dry scalping screen to remove any coarse debris. The sand and other
material that passes the dry scalping screen is conveyed to the wet processing plant, where it is washed, creating a sand slurry. The underflow sand slurry then
passes through a series of de-sliming cyclones and attrition scrubber cells that remove any free interstitial clays and grain-coating clays. The de-slimed sand
slurry is then de-watered by another series of cyclones and de-water screens as it is conveyed to the drain pad stockpile. Once on the drain pad, gravity helps to
naturally drain. This damp sand is then conveyed into one of the dry processing plant’s three rotary dryers. Within the dry processing plant, the sand is dried,
sized and sorted. The 40/70-mesh and 100-mesh dry finished products are stored in silos prior to loading into bulk trucks for shipment to customers in the
Permian Basin.

We are the first landowner to mine silica at the Lamesa site. Since purchasing the Lamesa property in 2017, we have invested funds to increase the
efficiency and expand the capacity of the Lamesa site. All buildings were constructed in 2018. We contract for the loading and hauling portion of the operations
at Lamesa. No U.S. Silica equipment is currently dedicated to the mine operations. Similarly, we primarily use leased mobile equipment in the processing plant.
We believe that the Lamesa site and its operating equipment are maintained in good working condition. The total net book value of the Lamesa site's real
property and fixed assets as of December 31, 2022 was $141.8 million.

Several natural and man-made features have been identified in and around the Lamesa site which may limit the mineable areas of the property. These
features include setbacks from neighboring properties, setbacks from oil production infrastructure and setbacks from existing utility corridors. We have included
suitable setbacks in our mining plans to avoid disturbing these areas.

Mining and processing activities on the Lamesa site are regulated by several federal and state laws. The Lamesa site is primarily environmentally
regulated by the Texas Commission on Environmental Quality (the "TCEQ"). However, the State of Texas does not require a mining permit to extract material.
The Lamesa site has secured and is operating in compliance with all required licenses, registrations, and permits.

A summary of Lamesa's mineral resources and reserves as of December 31, 2022 and 2021 is shown below (in thousands of tons). For more information

on our resources and reserves, please refer to Sections 11.0 and 12.0 of the Lamesa TRS.

45

Lamesa, TX - Summary of Resources

Classification

Amount 

(1)(2)(3)

Amount 

(1)(2)

Amount Change
2022 vs. 2021

Percent Change 2022
vs. 2021

December 31, 2022

December 31, 2021

Measured
Indicated

622 
4,748 
5,370 

— 
— 
— 

622 
4,748 
5,370 

100 %
100 %
100 %

5,002 
Item 1304(b)(2)(d)(2) of regulation S-K requires disclosure of resources to be exclusive of reserves. Unless otherwise noted, line items with no resources

     Total Measured + Indicated Resources
Inferred
(1) 
represent a 100% conversion of currently known geologic resources to mineable reserves.
(2)
 Only one commodity (proppant sand) is mined, processed and sold at the Lamesa site. Production of proppant sand is driven by market demand and can be
modified in response to that demand. As such, the application of minimum thicknesses, maximum stripping ratios, or cut-off grades is not generally considered
in the estimation of silica sand resources for the Lamesa site.
(3)

5,002 

 Mineral resources for Lamesa, TX are based on ASP of $31.39/ product ton.

— 

100 %

Lamesa, TX - Summary of Reserves

December 31, 2022

December 31, 2021

Amount Change
2022 vs. 2021

Percent Change 2022 vs.
2021

(1)

(2)(4)

(2)(3)(4)

Amount

Amount

7,633 
(5)
N/A

93,311 
69,983 

12,800 
9,600 

85,678 
(5)
N/A

Classification
Proven Reserves
Mineable
(5)
Saleable
Probable Reserves
Mineable
(5)
Saleable
Total Reserves
Mineable Total
(5)
Saleable Total
(1)
to customers. Lamesa's mine recovery rate is 95% and process recovery rate is 75%, resulting in an overall product yield of 71.3%
(2)
 Only one commodity (proppant sand) is mined, processed and sold at the Lamesa site. Production of proppant sand is driven by market demand and can be
modified in response to that demand. As such, the application of minimum thicknesses, maximum stripping ratios, or cut-off grades is not generally considered
in the estimation of silica sand reserves for the Lamesa site.
(3)

15 %
(5)
N/A
 Ore reserves are stated as "mineable" reserves (after mining losses) and saleable reserves (after processing plant losses) as finished product available for sale

 Lamesa, TX economic evaluation based on $23.90/ product ton; lower than 2022 ASP of $31.39/product ton. No price escalation used.
 Based on the lateral geologic continuity of Lamesa's sand dune deposits, Proven Ore is defined within 1/4-mile radius of a drill hole. Probable ore extends

(4)
out to 1/2-mile radius from a drill hole. No P+P ore is considered outside the "dune line" where dunes are absent.
(5)
reserves. In an effort to provide investors with a meaningful comparison during this period of transition, we have provided reserve estimates of both the
mineable and saleable tons for the fiscal year ended December 31, 2022. As the decision to report saleable reserves was not made until December 31, 2022,
saleable tons are not reported for the fiscal year ended December 31, 2021.

 On December 31, 2022, we determined to report our reserve estimates as saleable reserves. We have historically reported our reserve estimates as mineable

106,111 
79,583 

92,478 
(5)
N/A

13,633 
(5)
N/A

6,000 
(5)
N/A

6,800 
(5)
N/A

88 %
(5)
N/A

9 %
(5)

N/A

The increase in resources from 2021 to 2022 is primarily attributable to (1) geologic block model changes and (2) changes to the life of mine plan. The
increase in reserves from 2021 to 2022 is attributed to (1) depletion due to mining of approximately 5,871,000 mineable tons, and (2) revisions to mine plans
resulting in increases of approximately 19,428,000 mineable tons.

46

Key assumptions and parameters relating to the mineral reserves at the Lamesa site are discussed in Sections 11.0 and 12.0, respectively, of the Lamesa

TRS. Only material that can be economically, safely, and legally extracted is contained in these ore reserve estimates. Other key assumptions include the lateral
geologic continuity of the mineable dune sand ore strata; ore block model construction criteria; mine design elements (stable pit slope geometries, mining bench
height, pit floor limitations, pit dewatering, etc.); and setbacks (from property boundaries, power, natural gas, and water utility lines, oil well infrastructure; and
ore quality).

Ottawa, Illinois

U.S. Silica’s Ottawa Operation is a surface silica sand mining and processing operation located immediately west of the City of Ottawa in LaSalle
County, Illinois. The cities of Chicago and Peoria, Illinois, are located approximately 95 miles east-northeast and 75 miles southwest, respectively, of the
Ottawa Operation. Geographically, the Ottawa Operation’s processing plant is located at approximately 41° 20' 45.19" N latitude and 88° 52' 33.11" W
longitude.

47

48

The Ottawa site includes approximately 2,072 acres of surface and mineral rights that we own outright. The North Ottawa site and former mine site
covers 857 acres, the South Ottawa mine includes 1,215 acres. The St. Peter Sandstone has been extensively explored and mined on the Ottawa Operation. The
North Ottawa site was mined out by 2010, and exploration on the South Ottawa site began in the year 2000. U.S. Silica provided data for 225 drill holes, wells,
field measurements, and test holes in and around the South Ottawa site. These data were utilized to define the lateral extent, thickness, particle size distribution,
and mineralogy of the remaining St. Peter Sandstone reserves at the Ottawa Operation.

The site is accessible by city, county and state roads as well as by two railroads. Our Ottawa site has an extensive rail-car loading, storage, and handling
facility. Additionally, we have access to a privately-owned barge terminal that leases property from us. The Ottawa site is connected to the local electrical and
natural gas distribution systems. Potable water is provided to the plant location by the City of Ottawa's public water system. Additionally, we have a private
well at the mine site. The site has offices holding administrative, engineering, and operations staff. In addition, there are several buildings that house the
processing facilities plant maintenance and support facilities.

We acquired the Ottawa site in 1987 by merger with the Ottawa Silica Company, which historically used the property to produce whole grain and ground

silica for customers in industrial and specialty products end markets. Since acquiring the facility, we renovated and upgraded its production capabilities to
enable it to produce multiple products through various processing methods, including washing, hydraulic sizing, grinding, screening and blending. These
production techniques allow the Ottawa site to meet a wide variety of focused specifications on product composition from customers. As such, the Ottawa site
services multiple end markets, such as glass, building products, foundry, fillers and extenders, chemicals and oil and gas proppants. In November 2009, we
expanded the silica sand capacity by 500,000 tons. During the fourth quarter of 2011, we completed a follow-on expansion project that added an additional
900,000 tons of silica sand capacity. None of Ottawa's mining equipment is more than 15 years old. We believe that the Ottawa facility and its operating
equipment are maintained in good working condition. The total net book value of the Ottawa facility's real property and fixed assets as of December 31, 2022
was $73.3 million.

Current mining at the Ottawa Operation takes place on the South Ottawa pit, where the St. Peter Sandstone is excavated using conventional surface
mining methods. The first step in the mining process is the removal of the alluvial cover material, or “overburden,” from the sandstone layer. This is completed
by a third-party contractor who uses a tracked excavator and articulated haul trucks. Next, blast holes are drilled into the sandstone and charged with a blasting
agent. A front-end loader loads the sand into articulated haul trucks that carry the sand to a stockpile located on the pit floor. A bulldozer pushes sand from the
stockpile to a high-pressure water cannon, or “monitor,” that uses recycled water from the plant. The water stream breaks up larger chunks of sand and creates a
sand-water slurry that flows to a pump. The pump transfers the slurry to the processing plant.

At the processing plant, the sand slurry is fed to a washer that removes some of the ultrafines, which are pumped to tailings. From the washer, the slurry is
pumped to hydrosizers that separate the sand into coarse and fine particle size fractions. From this point forward, the two streams are processed in dedicated,
parallel circuits. Both streams are wet screened to remove oversized material, which is pumped to an abandoned pit. The screened sand is then thickened and
dewatered by vacuum filter belts before being fed to the four fluidized bed dryers. Dried fine sand from the dryers reports to a sizing system where screening
units sort the sand by grain size and store it in dedicated bins. A system of blending conveyors then produce sands, which are then loaded into bulk railcars or
trucks or bagged for specific end-use markets. Separate streams from the sizing operation feed the fine sand plant and grinding mills.

The fine sand processing plant was built in the 1950’s and consists of a screening system and sixteen product bins. The bagging processing plant is automated
and includes a warehouse for packaged product. Truck loading was upgraded in 1998. Whole grain products are shipped primarily to the foundry, glass and
hydraulic fracturing industries. The milling processing plant was commissioned in the 1940’s. Whole grain sand is pulverized in dry ball mills using ceramic
grinding balls to minimize product contamination. The mill discharge is air-classified, and the product is transported to storage bins for bulk loading or
packaging. The oversize grains are rejected by the classifiers and return to the mill feed for re-grinding in a closed loop.

Several natural and man-made features have been identified in and around the Ottawa site which may limit the mineable areas of the property. These

features include setbacks from neighboring properties, right of ways, marshes, brooks, wetlands and archaeologically significant sites.

To operate active mining operations on the property, the Illinois Department of Natural Resources, Department of Mines and Minerals required an
approved Land Reclamation Plan. Additional restrictions on the use of lands are included in other permits that are required by various Illinois State agencies to
operate the mine and plant. The Ottawa site has secured necessary permits and is operating in compliance with all required licenses, registrations, and permits.

49

A summary of Ottawa's mineral resources and reserves as of December 31, 2022 and 2021 is shown below (in thousands of tons). For more information

on our resources and reserves, please refer to Sections 11.0 and 12.0 of the Ottawa TRS.
Ottawa, IL - Summary of Resources

Classification

Amount 

(1)(2)(3)

Amount 

(1)(2)

Amount Change
2022 vs. 2021

Percent Change 2022
vs. 2021

December 31, 2022

December 31, 2021

Measured
Indicated

Item 1304(b)(2)(d)(2) of regulation S-K requires disclosure of resources to be exclusive of reserves. Unless otherwise noted, line items with no resources

     Total Measured + Indicated Resources
Inferred
(1) 
represent a 100% conversion of currently known geologic resources to mineable reserves.
(2)
production can be modified in response to that demand. As such, the application of minimum mining thicknesses, maximum stripping ratios, or cut-off grades
is not generally considered in the estimation of silica sand resources for the Ottawa site.
(3)

 Only one commodity (silica sand) is mined, processed and sold at the Ottawa site. Production of silica sand is driven by market demand. Silica sand

 Mineral resources for Ottawa, IL are based on ASP of $42.37/product ton.

88 

— 

88 

— 
— 
— 

— 
— 
— 

— 
— 
— 

— %
— %
— %

100 %

Ottawa, IL - Summary of Mineral Reserves

December 31, 2022 December 31, 2021

Amount Change
2022 vs. 2021

Percent Change 2022 vs.
2021

(1)

(2)(4)

(2)(3)(4)

Amount

Amount

1,486 
1,286 

89,742 
77,627 

22,815 
(5)
N/A

66,927 
(5)
N/A

Classification
Proven Reserves
Mineable
(5)
Saleable
Probable Reserves
Mineable
(5)
Saleable
Total Reserves
Mineable Total
Saleable Total
(1) 
sale to customers. Ottawa's mine recovery rate is 95% and process recovery rate is 86.5%, resulting in an overall product yield of 82.2%.
(2)
 Only one commodity (silica sand) is mined, processed and sold at the Ottawa site. Production of silica sand is driven by market demand. Silica sand
production can be modified in response to that demand. As such, the application of minimum mining thicknesses, maximum stripping ratios, or cut-off
grades is not generally considered in the estimation of silica sand reserves for the Ottawa site.
(3) 

Ore reserves are stated as "mineable" reserves (after mining losses) and saleable reserves (after processing plant losses) as finished product available for

Ottawa, IL economic evaluation based on $42.37/product ton; equal to 2022 ASP. No price esclation used.
 The St. Peter Sandstone occurs as a massive, thick sandstone stratum that is well defined geologically and well understood from historical mining. As

(4)
such, "reasonable" drill hole spacing in conjunction with mine exposures are used to define Proven Ore. Probable Ore has a more widely spaced drill
pattern in the same geologically continuous strata but absent of any mine development exposure.
(5)
mineable reserves. In an effort to provide investors with a meaningful comparison during this period of transition, we have provided reserve estimates of
both the mineable and saleable tons for the fiscal year ended December 31, 2022. As the decision to report saleable reserves was not made until December
31, 2022, saleable tons are not reported for the fiscal year ended December 31, 2021.

 On December 31, 2022, we determined to report our reserve estimates as saleable reserves. We have historically reported our reserve estimates as

(31,516)
(5)
N/A

33,002 
(5)
N/A

99,929 
(5)
N/A

91,228 
78,913 

(8,701)
(5)
N/A

(95)%
(5)
N/A

34 %
(5)
N/A

(9)%
(5)
N/A

50

The increase in resources from 2021 to 2022 is primarily attributable to (1) geologic block model changes and (2) changes to the life of mine plan. The
decrease in reserves from 2021 to 2022 is attributed to (1) depletion due to mining of approximately 3,230,000 mineable tons, and (2) revisions to mine plans
resulting in deductions of approximately 5,470,000 mineable tons.

Key assumptions and parameters relating to the mineral reserves at the Ottawa site are discussed in Sections 11.0 and 12.0, respectively, of the Ottawa

TRS. Only material that can be economically, safely, and legally extracted is contained in these ore reserve estimates. Other key assumptions include the lateral
geologic continuity of the ubiquitous St. Peter Sandstone ore strata; ore block model construction criteria; mine design elements (stable pit slope geometries,
mining bench height, ground control, pit dewatering, etc.); setbacks (from property boundaries, power, natural gas, and other utility lines); and ore quality).

Lovelock, Nevada - Colado Mine

Located in Pershing County, Nevada, U.S. Silica’s Colado site comprises a surface DE mining operation (the “Colado Mine”) and a DE processing plant
(the “Lovelock Processing Plant”) and is approximately 80 miles northeast of the City of Reno. The Lovelock Processing Plant is located seven miles northeast
of the City of Lovelock and the Colado Mine is located approximately 19 miles northwest of the plant. Geographically, the southeastern-most access to the
Colado Mine is located at approximately 40° 16' 29.66" N latitude and 118° 43' 41.51" W longitude. The Lovelock Processing Plant is located at approximately
40° 14' 45.51" N latitude and 118° 23' 25.35" W longitude.

51

52

We hold surface and/or mineral rights to approximately 9,526 acres across the two sites that comprise the Colado Operation. The Colado Mine property
comprises approximately 8,993 acres of private and federal lands leased from the Franco-Nevada U.S. Corporation (Franco-Nevada) and the U.S. Department
of the Interior’s Bureau of Land Management (BLM), respectively. The Lovelock Processing Plant property encompasses approximately 493 acres owned in fee
by U.S. Silica and 40 acres leased from the BLM.

The land lease with Franco-Nevada is for 3,842 acres of surface and mineral control at the Colado Mine and is renewed annually. The BLM leases
provide U.S. Silica with surface control on federal lands at both the Colado Mine and Lovelock Processing Plant properties. Mineral rights on the BLM-
administered lands at the Colado Mine are provided to U.S. Silica by way of 148 active mining claims, of which 132 are active placer claims. Mineral claims
are renewed on an annual basis. The Franco-Nevada U.S. Corporation leases are based on a royalty-type structure that considers the tons of product sold during
the lease period and how material used for the product tons sold was mined from each lease area. The leases also include a minimum annual amount to ensure a
minimum annual payment to the landowners. The royalty unit values are adjusted based on the Consumer Price Index, a statistical index that is calculated and
published annually by the U.S. Bureau of Labor Statistics. As for the federal land lease, the Bureau of Land Management publishes a mining claim fees
schedule on an annual basis.

The Colado site is remote with few improved roads and installed mine-related infrastructure. The site is accessible by private and state roads. Energy is
provided primarily by diesel powered equipment. Water requirements are primarily for dust suppression which is supplied by a municipal water source that is
trucked by tanker to the Colado mine. The only onsite buildings are a maintenance shelter used to service the mine equipment and a small portable office. The
existing infrastructure is adequate for current production levels and for the ramp-up of operations to full capacity.

The Colado site was initially commissioned in 1959. We acquired the Colado site in connection with the completion of the acquisition of EPM in May 2018.

Significant exploration had been undertaken by EPM (and affiliates) prior to our acquisition of the property in 2018. Throughout various exploration
campaigns, the subject DE deposits have been identified and delineated through geologic mapping, outcrop sampling, trenching, geophysical surveys, and
extensive exploration drilling. Despite Colado's long history, none of the site's mining equipment is more than 50 years old. We believe that the Colado site’s
facility and its operating equipment are maintained in good working condition. The total net book value of Colado's real property and fixed assets as of
December 31, 2022 was $25.1 million. The total net book value for the mine excludes the reserves because during purchase accounting we did not allocate the
reserves by mine and they are included at the corporate level.

The DE mining horizons at the Colado Mine are relatively shallow, quite thick, and are moderately dipping. These characteristics favor conventional surface
mining techniques. The Colado site is currently in the production phase. Mining occurs on benches, in a stair-like fashion, to remove the overburden waste
material and expose the DE beds. The Colado Mine maintains a stockpile of approximately 600,000 cubic yards at the mine site to meet the demands of the
processing plant. The raw ore is delivered by truck to the Lovelock Processing Plant.

At the plant, ore is fed into a crusher, where the ore is appropriately sized. The ore is fed into feed silos and then introduced into a flash dryer. There the ore is
heated and pneumatically transferred through the wet end of the process. Grit or heavy particles are classified and separated from the process as waste (about
10% of material), while all other material continues through the process. The classified ore is fed to a variable-speed natural gas rotary kiln, where it is
processed up to temperatures of 2,000 degrees Fahrenheit. Depending on the final product to be made, soda ash can be added to the kiln, in a process called
flux-calcining. The final product from the kiln is then fed to a series of classifiers to further sort the product into different size ranges. Material that is oversized
is fed to a hammer mill to be ground, and then to be re-processed; material that is undersized is sent to the fine filler circuit, and everything else is sent to
corresponding bins for the last step, packaging and shipping.

No significant encumbrances exist at the mine site. State and federal permits are required to mine the DE and operate the processing plant. Surface disturbance
is permitted as needed in accordance with state regulations. Major modifications to the permit are made as needed. We submitted a major modification
application during 2021 to address unpermitted disturbance, reclamation of erosion areas, and proposed expansions for continued DE mining operations. We
expect final approval of this application during 2023, however, its pending status does not negatively impact current mine operations.

53

A summary of Colado's DE mineral resources and reserves as of December 31, 2022 and 2021 is shown below (in thousands of tons). For more information on
our resources and reserves, please refer to Sections 11.0 and 12.0 of the Colado TRS.

Lovelock/Colado, NV - Summary of Resources

Classification

Amount 

(1)(2)(3)

Amount 

(1)(2)

Amount Change
2022 vs. 2021

Percent Change 2022
vs. 2021

December 31, 2022

December 31, 2021

Measured
Indicated

Item 1304(b)(2)(d)(2) of regulation S-K requires disclosure of resources to be exclusive of reserves. Unless otherwise noted, line items with no resources

     Total Measured + Indicated Resources
Inferred
(1) 
represent a 100% conversion of currently known geologic resources to mineable reserves.
(2)
be used to meet finished product specification, application of cut-off grades is not generally considered in the estimation of DE resources for the Colado site.
(3)

 Only one commodity (DE) is mined, processed and sold. The end use can result in multpile products based on customer need. Because targeted blending can

 Mineral resources for Lovelock/Colado, NV are based on ASP of $697.27/product ton.

689 

689 

— 

100 %

— 
— 
— 

— 
— 
— 

— %
— %
— %

— 
— 
— 

54

Lovelock, NV - Summary of Mineral Reserves

Classification

(1)

Amount

(2)(3)(4)

Amount

(2)(4)

Amount Change
2022 vs. 2021

Percent Change 2022
vs. 2021

December 31, 2022

December 31, 2021

1,671 
1,364 

Proven Reserves
Mineable
(5)
Saleable
Probable Reserves
Mineable
(5)
Saleable
Total Reserves
Mineable
Saleable(5)
(1)
to customers. Lovelock/Colado's mine recovery rate is 76.4% and process recovery rate is 81.6%, resulting in an overall site recovery of 62.3%.
(2)
 Only one commodity DE is mined, processed and sold at the Lovelock/Colado site. The end use can result in multiple products based on customer need.
Because targeted blending can be used to meet finished product specification, application of cut-off grades is not generally considered in the estimation of DE
reserves for the Lovelock/Colado site.
(3)

— %
4,479 
(5)
N/A
3,655 
 Ore reserves are stated as "mineable" reserves (after mining losses) and saleable reserves (after processing plant losses) as finished product available for sale

 Lovelock/Colado, NV economic evaluation based on $697.27/product ton; equal to 2022 ASP. No price escalation used.

4,461 
(5)
N/A

1,100 
(5)
N/A

3,361 
(5)
N/A

(16)%
(5)
N/A

2,808 
2,291 

52 %
(5)
N/A

(553)
(5)
N/A

571 
(5)

18 
(5)

N/A

N/A

(4) The DE ore at Colado occurs as layered, basin-controlled, lacustrine sedimentary deposits interbedded with volcanic ash deposits. As such, tighter drill hole
spacings are required to delineate ore reserves. Proven Ore is defined by drill hole spacings of less than 200-ft. and containing at least 5-ore intercepts.
Probable Ore is defined by drill hole spacing of less than 400-ft. and containing at least 3-ore intercepts.
(5) On December 31, 2022, we determined to report our reserve estimates as saleable reserves. We have historically reported our reserve estimates as mineable
reserves. In an effort to provide investors with a meaningful comparison during this period of transition, we have provided reserve estimates of both the
mineable and saleable tons for the fiscal year ended December 31, 2022. As the decision to report saleable reserves was not made until December 31, 2022,
saleable tons are not reported for the fiscal year ended December 31, 2021.

The increase in resources from 2021 to 2022 is primarily attributable to (1) geologic block model changes and (2) changes to the life of mine plan. The

increase in reserves from 2021 to 2022 is primarily attributable to (1) depletion due to mining of approximately 175,000 mineable tons and (2) revisions to mine
plans resulting in net increases of approximately 193,000 mineable tons.

Key assumptions and parameters relating to the mineral reserves at Colado are discussed in Sections 11.0 and 12.0, respectively, of the Colado TRS.
Among them are assumptions with respect to geologic continuity of the ore; specific chemical and physical characteristics of the DE deposits; mine design
criteria defining safe, efficient and "mineable" geometries (stable pit designs, mining bench height, ground control, economic overburden stripping ratios, haul
road design, pit floor design, waste mining and backfill requirements; and ore stockpile management).

Internal Controls Disclosure

The modeling and analysis of our reserves has been developed by our personnel, reviewed by several levels of internal management and, in the case of

the four material properties, audited by JT Boyd. This section summarizes the internal control considerations for our development of estimations, including
assumptions, used in resource and reserve analysis and modeling.

When determining resources and reserves, as well as the differences between resources and reserves, management developed specific criteria, each of

which must be met to qualify as a resource or reserve, respectively. These criteria, such as

55

demonstration of economic viability, repeatable geologic continuity, and meeting generally accepted quality specifications, are specific and attainable, as
applicable. Calculations using site specific criteria for the four material properties were reviewed by JT Boyd. JT Boyd was provided with our exploration data,
geologic models, and volumetric estimates and took a three-step approach to validate our resource and reserve estimates at the four material properties: (1)
verified the accuracy of geologic model inputs by comparison with drilling logs and laboratory reports, (2) compared the geologic model with compiled drilling
data and (3) prepared a stratigraphic grid model of the geologic unit and independently estimated pit shell volumes. All calculations were conducted
independently by JT Boyd, then compared to our internal estimates and found to be within acceptable variance. A detailed description of the methodology used
to calculate mineral reserves for the four material properties is provided in the TRSs filed as exhibits to this Annual Report.

For all properties, geographical modeling and mine planning efforts serve as a base assumption for resource and reserve estimates at each location. These

outputs have been prepared by both our personnel and third-party consultants, and the methodology is compared to industry best practices. Mine planning
decisions, such as mining bench height, execution of mining processes and ground control, are determined and agreed upon by our management. Management
adjusts forward-looking models by reference to historic mining results, including reviewing performance versus predicted levels of production from the mineral
deposit, and if necessary, re-evaluating mining methodologies if production outcomes were not realized as predicted. Ongoing mining and investigation of the
mineral deposit, coupled with product quality validation pursuant to industry best practices and customer expectations, provides further empirical evidence as to
the homogeneity, continuity and characteristics of the mineral resource. Ongoing quality validation of production also provides a means to monitor for any
potential changes in ore-body quality.

Management also assesses risks inherent in mineral resource and reserve estimates, such as the accuracy of geological data that is used to support mine

planning, identify hazards and inform operations of the presence of mineable deposits. Also, management is aware of risks associated with potential gaps in
assessing the completeness of mineral extraction licenses, entitlements or rights, or changes in laws or regulations that could directly impact the ability to assess
mineral resources and reserves or impact production levels. Risks inherent in overestimated reserves can impact financial performance when revealed, such as
changes in amortization that are based on life of mine estimates. Quarterly, and as part of our SOX compliance guidelines, a review meeting is held with senior
leadership from operations, finance, mine planning, and environmental to review the overall ore reserve changes and any potential impacts to our site asset
retirement obligations or site financial metrics.

56

 
                
ITEM 3.

LEGAL PROCEEDINGS

    In addition to the matters described below, we are subject to various legal proceedings, claims, and governmental inspections, audits or investigations
incidental to our business, which can cover general commercial, governmental regulations, antitrust and trade regulations, product liability, environmental,
intellectual property, employment and other matters. Although the outcomes of these ordinary routine claims cannot be predicted with certainty, in the opinion
of management, the ultimate resolution of these matters will not have a material adverse effect on our financial position or results of operations.

    Prolonged inhalation of excessive levels of respirable crystalline silica dust can result in silicosis, a disease of the lungs. Breathing large amounts of
respirable silica dust over time may injure a person’s lungs by causing scar tissue to form. Crystalline silica in the form of quartz is a basic component of soil,
sand, granite and most other types of rock. Cutting, breaking, crushing, drilling, grinding and abrasive blasting of or with crystalline silica containing materials
can produce fine silica dust, the inhalation of which may cause silicosis, lung cancer and possibly other diseases including immune system disorders such as
scleroderma. Sources of exposure to respirable crystalline silica dust include sandblasting, foundry manufacturing, crushing and drilling of rock, masonry and
concrete work, mining and tunneling, and cement and asphalt pavement manufacturing.

    Since at least 1975, we and/or our predecessors have been named as a defendant, usually among many defendants, in numerous lawsuits brought by or on
behalf of current or former employees of our customers alleging damages caused by silica exposure. Prior to 2001, the number of silicosis lawsuits filed
annually against the commercial silica industry remained relatively stable and was generally below 100, but between 2001 and 2004 the number of silicosis
lawsuits filed against the commercial silica industry substantially increased. This increase led to greater scrutiny of the nature of the claims filed, and in June
2005 the U.S. District Court for the Southern District of Texas issued an opinion in the former federal silica multi-district litigation remanding almost all of the
10,000 cases then pending in the multi-district litigation back to the state courts from which they originated for further review and medical qualification, leading
to a number of silicosis case dismissals across the United States. In conjunction with this and other favorable court rulings establishing “sophisticated user” and
“no duty to warn” defenses for silica producers, several states, including Texas, Ohio and Florida, have passed medical criteria legislation that requires proof of
actual impairment before a lawsuit can be filed.

    As a result of the above developments, the filing rate of new claims against us over the past few years has decreased to below pre-2001 levels, and we were
named as a defendant in zero, two, and one new silicosis cases filed in 2022, 2021 and 2020, respectively. As of December 31, 2022, there were 42 active silica-
related product liability claims pending in which U.S. Silica is a defendant. Almost all of the claims pending against us arise out of the alleged use of our silica
products in foundries or as an abrasive blast media and involve various other defendants. Prior to the fourth quarter of 2012, we had insurance policies for our
predecessors that cover certain claims for alleged silica exposure for periods prior to certain dates in 1985 and 1986 (with respect to certain insurance). As a
result of a settlement with a former owner and its insurers in the fourth quarter of 2012, some of these policies are no longer available to us and we will not seek
reimbursement for any defense costs or claim payments from these policies. Other insurance policies, however, continue to remain available to us and will
continue to make such payments on our behalf.

    The silica-related litigation brought against us to date has not resulted in material liability to us. However, we continue to have silica-related product liability
claims filed against us, including claims that allege silica exposure for periods for which we do not have insurance coverage. Although the outcomes of these
claims cannot be predicted with certainty, in the opinion of management, it is not reasonably possible that the ultimate resolution of these matters will have a
material adverse effect on our financial position or results of operations that exceeds the accrual amounts. For more information regarding silica-related
litigation, see Part I, Item 1A. Risk Factors of this Annual Report on Form 10-K and Note P - Commitments and Contingencies to our Consolidated Financial
Statements in Part II, Item 8 of this Annual Report on Form 10-K.

ITEM 4.

MINE SAFETY DISCLOSURES

Safety is one of our core values and we strive to achieve a workplace free of injuries and occupational illnesses. Our health and safety leadership team has

developed comprehensive safety policies and standards, which include detailed standards and procedures for safe production and address topics such as
employee training, risk management, workplace inspection, emergency response, accident investigation and program auditing. We place special emphasis on
the importance of continuous improvement in occupational health, personal injury avoidance and prevention, emergency preparedness, and property damage
elimination. In addition to strong leadership and involvement from all levels of the organization, these programs and procedures form the cornerstone of our
safety initiatives and are intended as a means to reduce workplace accidents, incidents and losses, comply with all mining-related regulations and provide
support for both regulators and the industry to improve mine safety.

57

While we want to have productive operations in full regulatory compliance, we know it is equally essential that we motivate and train our people to think,
practice and feel a personal responsibility for health and safety on and off the job.

All of our production facilities, with the exception of our Blair, Nebraska, facility, are classified as mines and are subject to regulation by MSHA under the

Mine Act. MSHA inspects our mines on a regular basis and issues various citations and orders when it believes a violation has occurred under the Mine Act.
Information concerning mine safety violations or other regulatory matters required by Section 1503(a) of the Dodd-Frank Wall Street Reform and Consumer
Protection Act and Item 104 of Regulation S-K (17 CFR 229.104) is included in Exhibit 95.1 to this Annual Report filed on Form 10-K.

PART II.

ITEM 5.

MARKET FOR REGISTRANT’S COMMON EQUITY, RELATED STOCKHOLDER MATTERS AND ISSUER PURCHASES OF
EQUITY SECURITIES

Market Information

Shares of our common stock, traded under the symbol “SLCA”, have been listed and publicly traded on the New York Stock Exchange since February 1,

2012.

Holders of Record

On February 17, 2023, there were 76,120,988 shares of our common stock outstanding, which were held by approximately 23 stockholders of record.

Because many of our shares of common stock are held by brokers and other institutions on behalf of beneficial owners, we are unable to estimate the total
number of stockholders represented by these record holders. For additional information related to ownership of our stock by certain beneficial owners and
management, refer to Part III, Item 12. Security Ownership of Certain Beneficial Owners and Management and Related Stockholder Matters of this Annual
Report on Form 10-K.

Purchase of Equity Securities by the Issuer

From time to time, we repurchase our common stock in the open market pursuant to programs approved by our Board of Directors. We may repurchase

our common stock for a variety of reasons, such as to offset dilution related to equity-based incentives and to optimize our capital structure.

We consider several factors in determining when to make share repurchases including, among other things, our cash needs, the availability of funding, our

future business plans and the market price of our stock. We expect that cash provided by future operating activities, as well as available liquidity, will be the
sources of funding for our share repurchase program.

The following table presents the total number of shares of our common stock that we purchased during the fourth quarter of 2022, the average price paid

per share, the number of shares that we repurchased as part of our share repurchase program, and the approximate dollar value of shares that still could have
been repurchased at the end of the applicable fiscal period pursuant to our share repurchase program:

Period
October 1, 2022 - October 31, 2022
November 1, 2022 - November 30, 2022
December 1, 2022 - December 31, 2022
Total

Total Number of
Shares Withheld or
Forfeited 

(2)

Average Price
Paid Per
Share

Total Number of
Shares Purchased as
Part of Publicly
Announced Program

(1)

Maximum Dollar Value of
Shares that May Yet
Be Purchased Under
the Program

(1)

31,321 
7,869 
4,130 
43,320 

$
$
$
$

12.15 
13.77 
12.18 
12.45 

—  $
—  $
—  $
— 

126,540,060 
126,540,060 
126,540,060 

(1)

(2)

In May 2018, our Board of Directors authorized and announced the repurchase of up to $200 million of our common stock from time to time on the
open market or in privately negotiated transactions. Stock repurchases, if any, will be funded using our available liquidity. The timing and amount of
stock repurchases will depend on a variety of factors, including the market conditions as well as corporate and regulatory considerations. As of
December 31, 2022, we have repurchased a total of 5,036,139 shares of our common stock at an average price of $14.59.
Represents shares withheld by U.S. Silica to pay taxes due upon the vesting of employee restricted stock and restricted stock units for the months ended
October 31, November 30 and December 31, 2022, respectively.

58

 
 
 
    We did not repurchase any shares of common stock under our share repurchase program during the three months ended December 31, 2022.

U.S. Silica Holdings, Inc. Comparative Stock Performance Graph

The information contained in this U.S. Silica Holdings, Inc. Comparative Stock Performance Graph section shall not be deemed to be "soliciting

material" or "filed" or incorporated by reference in future filings with the SEC, or subject to the liabilities of Section 18 of the Exchange Act, except to the
extent that we specifically incorporate it by reference into a document filed under the Securities Act or the Exchange Act.

The graph below compares the cumulative total shareholder return on our common stock to the cumulative total return on the Russell 3000 index and the
Standard and Poor’s SmallCap 600 Energy Sector index, in each case assuming $100 was invested on December 31, 2017 and the reinvestment of all dividends.
We elected to include the Standard and Poor’s SmallCap 600 Energy Sector index because a number of companies in this index are included in the custom peer
group used to determine relative total shareholder return performance share units that we have granted to employees.

59

 
 
Unregistered Sales of Equity Securities

None.

ITEM 6.

SELECTED FINANCIAL DATA

[Reserved]

ITEM 7.

MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS

    The following discussion and analysis of our financial condition and results of operations should be read together with the description of the business
appearing in Item 1. Business and the Consolidated Financial Statements in Item 8. Financial Statements and Supplementary Data of this Annual Report on
Form 10-K.

    This discussion contains forward-looking statements, as discussed under "Forward-Looking Statements". These statements are based on current expectations
and assumptions and are subject to risks and uncertainties. Actual results could differ materially from those discussed in or implied by forward-looking
statements. Factors that could cause or contribute to these differences include those discussed below and elsewhere in this report, particularly under "Forward-
Looking Statements" and in Item 1A. Risk Factors of this Annual Report on Form 10-K.

    Adjusted EBITDA and segment contribution margin as used herein are non-GAAP measures. For a detailed description of Adjusted EBITDA and segment
contribution margin and reconciliations to their most comparable GAAP measures, please see the discussion below under “How We Evaluate Our Business.”

Overview

    We are a global performance materials company and a leading producer of commercial silica used in the oil and gas industry and in a wide range of industrial
applications. In addition, through our subsidiary EP Minerals, LLC ("EPM") we are an industry leader in the production of industrial minerals, including
diatomaceous earth, clay (calcium bentonite and calcium montmorillonite), and perlite.

    During our 123-year history, we have developed core competencies in mining, processing, logistics and materials science that enable us to produce and cost-
effectively deliver over 600 diversified product types to customers across our end markets. As of December 31, 2022, we had 27 operating mines and
processing facilities and two additional exploration stage properties across the United States. We control 468 million tons of reserves of commercial silica,
which can be processed to make 182 million tons of finished products that meet API frac sand specifications, and 82 million tons of reserves of diatomaceous
earth, perlite, and clays.

    Our operations are organized into two reportable segments based on end markets served and the manner in which we analyze our operating and financial
performance: (1) Oil & Gas Proppants and (2) Industrial & Specialty Products. We believe our segments are complementary because our ability to sell to a wide
range of customers across end markets in these segments allows us to maximize recovery rates in our mining operations and optimize our asset utilization.

Recent Trends and Outlook

Oil and gas proppants end market trends

Our operations in our Oil & Gas Proppants segment are materially dependent on the levels of activity in natural gas and oil exploration, development

and production, which are affected by trends in natural gas and oil prices. In recent years, natural gas and oil prices and, therefore, the level of exploration,
development, and production activity, have experienced significant volatility.

During 2020, the COVID-19 pandemic and related economic repercussions, coupled with an inadequate supply response and exacerbated by the lack

of global storage capacity, resulted in a precipitous decline in crude oil prices. Demand for our proppant and logistics services declined as our customers
reduced their capital spending budgets and drilling and completion operations in response to lower oil prices. Crude oil prices began to rebound from 2020
levels, with the West Texas Intermediate price of crude oil increasing 55% during 2021 and 7% during 2022. This resulted in strong well completion activity
and improved pricing for our Oil & Gas Proppants segment. Strong customer demand and favorable pricing in this segment continued throughout 2022, offset
in part by higher transportation and other costs.

60

The conflict between Russia and Ukraine has increased the disruption, instability and volatility in global markets and industries. As our operations are

significantly U.S. based, we have not been, to date, materially impacted by this conflict. We continue to monitor the uncertainty surrounding the extent and
duration of this ongoing conflict and the impact that it may have on the global economy and on our business.

Heightened levels of inflation present risk for us in terms of increased labor costs, transportation costs and energy costs that may not be able to be

passed on to customers through increased pricing. In addition, rising interest rates will increase our borrowing costs on new and existing debt.

During the three months ended December 31, 2022, frac sand demand, average selling price and tons sold increased compared to the three months

ended September 30, 2022, as summarized below. Sales increased by 10% or $23.2 million in our Oil & Gas Proppants segment during the three months ended
September 30, 2022 compared to the three months ended June 30, 2022 and increased by 39% or $68.0 million during the three months ended June 30, 2022
compared to the three months ended March 31, 2022. This was primarily due to higher energy prices and a rebound in overall well completion activity.

Amounts in thousands,
except per ton data

Oil & Gas Proppants
Sales
Tons Sold
Average Selling
Price per Ton

$

$

Three Months Ended

Percentage Change for the Three Months Ended

December 31,
2022

September 30,
2022

June 30, 2022

March 31, 2022

December 31, 2022
vs. September 30,
2022

September 30,
2022 vs. June 30,
2022

June 30, 2022 vs.
March 31, 2022

273,717  $
3,568 

267,461 
3,498 

76.71  $

76.46 

$

$

244,246  $
3,528 

176,244 
3,060 

69.23  $

57.60 

2 %
2 %

— %

10 %
(1)%

10 %

39 %
15 %

20 %

If oil and gas drilling and completion activity does not grow, or if frac sand supply remains greater than demand, then we may sell fewer tons, sell tons
at lower prices, or both. If we sell less frac sand or sell frac sand at lower prices, our revenue, net income, cash generated from operating activities, and liquidity
would be adversely affected, and we could incur material asset impairments. If these events occur, we may evaluate actions to reduce costs and improve
liquidity.

Industrial and specialty products end market trends

Demand in the industrial and specialty products end markets has been relatively stable in recent years and is primarily influenced by key
macroeconomic drivers such as housing starts, population growth, light vehicle sales, beer and wine production, repair and remodel activity and industrial
production. The primary end markets served by our Industrial & Specialty Products segment are building and construction products, fillers and extenders,
filtration, glassmaking, absorbents, foundry, and sports and recreation. We have been increasing our value-added product offerings in the industrial and
specialty products end markets organically as well as through acquisitions, such as White Armor and EPM. Additionally, we have increased our focus on the
alternative energy markets and products necessary for the supply chains of solar panels, renewable diesel and wind turbines. Sales of these new higher margin
products have increased our Industrial & Specialty Products segment's profitability.

Heightened levels of inflation present risk for us in terms of increased labor costs, transportation costs and energy costs that may not be able to be

passed on to customers through increased pricing. In addition, rising interest rates will increase our borrowing costs on new and existing debt. Additionally, we
continue to monitor the uncertainty surrounding the extent and duration of the Russia and Ukraine conflict on our business as discussed above.

The COVID-19 pandemic caused severe economic, market and other disruptions worldwide, which began to affect our Industrial & Specialty Products

segment in the second quarter of 2020. Even as the COVID-19 pandemic has subsided, we may continue to experience adverse impacts in this segment as a
result of any long-term impacts resulting from the pandemic in the relevant markets.

Review of Strategic Alternatives

On June 13, 2022, we announced that we had concluded the review of strategic alternatives for our Industrial & Specialty Products ("ISP") segment
which had been initiated in October 2021. We stated that, after extensive review and deliberation, and in consultation with our independent financial and legal
advisors, the Board of Directors unanimously determined that retaining ownership of the ISP segment represented the best path forward for U.S Silica and our
shareholders.

61

Our Business Strategy

The key drivers of our strategy include:

•

•

•

•

•

increasing our presence and product offerings in specialty products end markets;

optimizing our product mix and further developing value-added capabilities to maximize margins;

effectively positioning our Oil & Gas Proppants facilities to optimally serve our customers;

optimizing our supply chain network and leveraging our logistics capabilities to meet our customers’ needs;

evaluating both Greenfield and Brownfield expansion opportunities and other acquisitions; and

• maintaining financial strength and flexibility.

For additional information about our key business strategies, see the discussion under “Our Business Strategy and Strengths” in Item 1. Business of this

Annual Report on Form 10-K.

How We Generate Our Sales

    Products

    We derive our product sales by mining and processing minerals that our customers purchase for various uses. Our product sales are primarily a function of the
price per ton and the number of tons sold. We primarily sell our products through individual purchase orders executed under short-term price agreements or at
prevailing market rates. The amount invoiced reflects the price of the product, transportation, surcharges, and additional handling services as applicable, such as
storage, transloading the product from railcars to trucks and last mile logistics to the customer site. We invoice most of our product customers on a per shipment
basis, although for some larger customers, we consolidate invoices weekly or monthly. Standard collection terms are net 30 days, although extended terms are
offered in competitive situations.

    Services

    We derive our service sales primarily through the provision of transportation, equipment rental, and contract labor services to companies in the oil and gas
industry. Transportation services typically consist of transporting customer proppant from storage facilities to proximal well-sites and are contracted through
work orders executed under established pricing agreements. The amount invoiced reflects transportation services rendered. Equipment rental services provide
customers with use of either dedicated or nonspecific wellhead proppant delivery equipment solutions for contractual periods defined either through formal
lease agreements or executed work orders under established pricing agreements. The amounts invoiced reflect the length of time the equipment set was utilized
in the billing period. Contract labor services provide customers with proppant delivery equipment operators through work orders executed under established
pricing agreements. The amounts invoiced reflect the amount of time our labor services were utilized in the billing period. We typically invoice our customers
on a weekly or monthly basis; however, some customers receive invoices upon well-site operation completion. Standard collection terms are net 30 days,
although extended terms are offered in competitive situations.

    Our ten largest customers accounted for approximately 40%, 40% and 34% of total sales during the years ended December 31, 2022, 2021 and 2020,
respectively. No single customer accounted for more than 10% of our total sales during the years ended December 31, 2022, 2021 and 2020. At December 31,
2022 and 2021, none of our customers' accounts receivable represented 10% or more of our total trade accounts receivable.

    For a limited number of customers, we sell under long-term, minimum purchase supply agreements. These agreements define, among other commitments, the
volume of product that our customers must purchase, the volume of product that we must provide, and the price that we will charge and that our customers will
pay for each product. Prices under these agreements are generally fixed and subject to certain contractual adjustments. Sometimes these agreements may
undergo negotiations regarding pricing and volume requirements, particularly in volatile market conditions. When these negotiations occur, we may deliver
sand at prices or at volumes below the requirements in our existing supply agreements. We do not consider these agreements solely representative of contracts
with customers. An executed order specifying the type and quantity of product to be delivered, in combination with the noted agreements, comprise our
contracts in these arrangements. Selling more tons under supply contracts enables us to be more efficient from a production, supply chain, and logistics
standpoint. As discussed in Part I, Item 1A., Risk Factors of this Annual Report on Form 10-K, these customers may not continue to purchase the same levels of
product in the future due to a variety of reasons, contract requirements notwithstanding.

    As of December 31, 2022, we had 12 minimum purchase supply agreements in the Oil & Gas Proppants segment with initial terms expiring between 2023
and 2034. As of December 31, 2021, we had eight minimum purchase supply agreements in the Oil & Gas Proppants segment with initial terms expiring
between 2022 and 2034. Collectively, sales to customers with

62

minimum purchase supply agreements accounted for 52% and 38% of Oil & Gas Proppants segment sales during the years ended December 31, 2022 and 2021,
respectively.

    In the industrial and specialty products end markets we have not historically entered into long-term minimum purchase supply agreements with our
customers because of the high cost to our customers of switching providers. We may periodically do so when capital or other investment is required to meet
customer needs. Instead, we often enter into supply agreements with our customers with targeted volumes and terms of one to five years. Prices under these
agreements are generally fixed and subject to annual increases.

The Costs of Conducting Our Business

    The principal expenses involved in conducting our business are transportation costs, labor costs, electricity and drying fuel costs, and maintenance and repair
costs for our mining and processing equipment and facilities. Transportation and related costs include freight charges, fuel surcharges, transloading fees,
switching fees, railcar lease costs, demurrage costs, storage fees and labor costs. Our operating costs can vary significantly based on the volume of product
produced and current economic conditions. We benefit from owning the majority of the mineral deposits that we mine and having long-term mineral rights
leases or supply agreements for our other primary sources of raw material, which limits royalty payments.

    Additionally, we incur expenses related to our corporate operations, including costs for sales and marketing; research and development; and the finance, legal,
human resources, information technology, and environmental, health and safety functions of our organization. These costs are principally driven by personnel
expenses.

How We Evaluate Our Business

    Our management team evaluates our business using a variety of financial and operating metrics. We evaluate the performance of our two segments based on
their tons sold, average selling price and contribution margin earned. Additionally, we consider a number of factors in evaluating the performance of our
business as a whole, including total tons sold, average selling price, total segment contribution margin, and Adjusted EBITDA. We view these metrics as
important factors in evaluating our profitability and review these measurements frequently to analyze trends and make decisions, and we believe the
presentation of these metrics provides useful information to our investors regarding our financial condition and results of operations for the same reasons.

Segment Contribution Margin

    Segment contribution margin, a non-GAAP measure, is a key metric that management uses to evaluate our operating performance and to determine resource
allocation between segments. Segment contribution margin excludes selling, general, and administrative costs, corporate costs, plant capacity expansion
expenses, and facility closure costs.

    Segment contribution margin is not a measure of our financial performance under GAAP and should not be considered an alternative measure or superior to
measures derived in accordance with GAAP. Our measure of segment contribution margin is not necessarily comparable to other similarly titled captions of
other companies due to potential inconsistencies in the methods of calculation. For more information about segment contribution margin, including a
reconciliation of this measure to its most directly comparable GAAP financial measure, net income (loss), see Note V - Segment Reporting to our Consolidated
Financial Statements in Part II, Item 8. of this Annual Report on Form 10-K.

Adjusted EBITDA

    Adjusted EBITDA, a non-GAAP measure, is included in this report because it is a key metric used by management to assess our operating performance and
by our lenders to evaluate our covenant compliance. Adjusted EBITDA excludes certain income and/or costs, the removal of which improves comparability of
operating results across reporting periods. Our target performance goals under our incentive compensation plan are tied, in part, to our Adjusted EBITDA.

63

    Adjusted EBITDA is not a measure of our financial performance or liquidity under GAAP and should not be considered as an alternative or superior to net
income (loss) as a measure of operating performance, cash flows from operating activities as a measure of liquidity or any other performance measure derived
in accordance with GAAP. Additionally, Adjusted EBITDA is not intended to be a measure of free cash flow for management’s discretionary use, as it does not
consider certain cash requirements such as interest payments, tax payments and debt service requirements. Adjusted EBITDA contains certain other limitations,
including the failure to reflect our cash expenditures, cash requirements for working capital needs and cash costs to replace assets being depreciated and
amortized, and excludes certain charges that may recur in the future. Management compensates for these limitations by relying primarily on our GAAP results
and by using Adjusted EBITDA only supplementally. Our measure of Adjusted EBITDA is not necessarily comparable to other similarly titled captions of other
companies due to potential inconsistencies in the methods of calculation.

    The following table sets forth a reconciliation of net income (loss), the most directly comparable GAAP financial measure, to Adjusted EBITDA.

(amounts in thousands)

Year ended December 31,

Net income (loss) attributable to U.S. Silica Holdings, Inc.
Total interest expense, net of interest income
Provision for taxes
Total depreciation, depletion and amortization expenses

EBITDA

(1)

(3)

(2)

Non-cash incentive compensation 
Post-employment expenses (excluding service costs) 
Merger and acquisition related expenses 
Plant capacity expansion expenses 
Contract termination expenses 
Goodwill and other asset impairments 
Business optimization projects 
Facility closure costs 
Gain on valuation change of royalty note payable 
Other adjustments allowable under the Credit Agreement 

(6)

(7)

(4)

(5)

(9)

(8)

(10)

Adjusted EBITDA

64

2022

78,176  $
75,437 
26,159 
140,166 
319,938 
19,653 
(2,654)
6,984 
213 
6,500 
— 
1,209 
1,503 
— 
212 
353,558  $

2021
(33,761) $
69,173 
(2,755)
161,131 
193,788 
19,692 
(1,920)
2,961 
928 
— 
202 
105 
1,347 
— 
6,372 
223,475  $

$

$

2020
(114,094)
79,148 
(60,025)
155,568 
60,597 
15,827 
1,729 
1,423 
6,149 
— 
110,688 
67 
7,093 
(8,263)
8,612 
203,922 

 
(1)

(2)

(3)

(4)

(5)

(6)

(7)

(8)

(9)

(10)

Reflects equity-based, non-cash compensation expense.
Includes net pension cost and net post-retirement cost relating to pension and other post-retirement benefit obligations during the applicable period, but
in each case excluding the service cost relating to benefits earned during such period. Non-service net periodic benefit costs are not considered
reflective of our operating performance because these costs do not exclusively originate from employee services during the applicable period and may
experience periodic fluctuations as a result of changes in non-operating factors, including changes in discount rates, changes in expected returns on
benefit plan assets, and other demographic actuarial assumptions. See Note Q - Pension and Post-Retirement Benefits to our Consolidated Financial
Statements in Part II, Item 8 of this Annual Report on Form 10-K for more information.

Merger and acquisition related expenses include legal fees, professional fees, bank fees, severance costs, and other employee related costs. While these
costs are not operational in nature and are not expected to continue for any singular transaction on an ongoing basis, similar types of costs, expenses and
charges have occurred in prior periods and may recur in the future as we continue to integrate prior acquisitions and pursue any future acquisitions.

Plant capacity expansion expenses include expenses that are not inventoriable or capitalizable as related to plant expansion projects greater than $5
million in capital expenditures or plant start up projects. While these expenses are not operational in nature and are not expected to continue for any
singular project on an ongoing basis, similar types of expenses have occurred in prior periods and may recur in the future.
Reflects contract termination expenses related to strategically exiting a supplier service contract. While these expenses are not operational in nature and
are not expected to continue for any singular event on an ongoing basis, similar types of expenses have occurred in prior periods and may recur in the
future as we continue to strategically evaluate our contracts.
See Note X - Impairments to our Consolidated Financial Statements in Part II, Item 8 of this Annual Report on Form 10-K for additional information.
While these expenses are not operational in nature and are not expected to continue for any singular event on an ongoing basis, similar types of
expenses have occurred in prior periods and may recur in the future.

Reflects costs incurred related to business optimization projects mainly within our corporate center, which aim to measure and improve the efficiency,
productivity and performance of our organization. While these costs are not operational in nature and are not expected to continue for any singular
project on an ongoing basis, similar types of expenses may recur in the future. 
Reflects costs incurred mainly related to idled sand facilities and closed corporate offices, including severance costs and remaining contracted costs such
as office lease costs, and common area maintenance fees. While these costs are not operational in nature and are not expected to continue for any
singular event on an ongoing basis, similar types of expenses may recur in the future.
Gains on valuation change of royalty note payable due to a change in estimate of future tonnages and sales related to the sand shipped from our Tyler,
Texas facility. These gains are not operational in nature and are not expected to continue for any singular event on an ongoing basis. See Note K - Debt
to our Consolidated Financial Statements in Part II, Item 8 of this Annual Report on Form 10-K for additional information.
Reflects miscellaneous adjustments permitted under the Credit Agreement such as recruiting fees and relocation costs. The year ended December 31,
2022 also included costs related to weather events and supplier and logistical issues of $1.1 million, severance restructuring costs of $1.8 million, an
adjustment to non-controlling interest of $0.6 million, partially offset by net proceeds of the sale of assets of $1.7 million and $2.9 million related to the
gain on extinguishment of debt. The year ended December 31, 2021 also included $3.4 million of transload shortfall and exit fees, $2.1 million related
to expenses incurred with severe winter storms during the first quarter, $0.7 million of costs related to a power interruption at a plant location, partially
offset by $0.1 million for a measurement period adjustment related to the Arrows Up bargain purchase. The year ended December 31, 2020 also
included $1.6 million in transload shortfalls and exit fees, $4.6 million in inventory adjustments, $6.0 million in severance costs, and $11.8 million in
legal expense due to the unsuccessful defense of a small number of our patents, offset by $15.2 million related to the gain attributable to the bargain
purchase of Arrows Up.

65

 
 
 
 
 
 
    
    Adjusted EBITDA-Trailing Twelve Months

    Our Revolver contains a covenant that we maintain a consolidated total net leverage ratio of no more than 3.75:1.00 that, unless we have the consent of our
lenders, we must meet as of the last day of any fiscal quarter whenever usage of the Revolver (other than certain undrawn letters of credit) exceeds 30% of the
Revolver commitment. This ratio is calculated based on our Adjusted EBITDA for the trailing twelve months. Noncompliance with this financial ratio covenant
could result in the acceleration of our obligations to repay all amounts outstanding under the Revolver and the term loan (the "Term Loan") (collectively the
"Credit Facility"). Moreover, the Revolver and the Term Loan contain covenants that restrict, subject to certain exceptions, our ability to make permitted
acquisitions, incur additional indebtedness, make restricted payments (including dividends) and retain excess cash flow based, in some cases, on our ability to
meet leverage ratios calculated based on our Adjusted EBITDA for the trailing twelve months.

    See the description under “Adjusted EBITDA” above for certain important information about Adjusted EBITDA-trailing twelve months, including certain
limitations and management’s use of this metric in light of its status as a non-GAAP measure.

    As of December 31, 2022, we are in compliance with all covenants under our Credit Facility, and our Revolver usage was zero (other than certain undrawn
letters of credit). Since the Revolver usage did not exceed 30% of the Revolver commitment, the consolidated leverage ratio covenant did not apply. Based on
our consolidated leverage ratio of 2.99:1.00 as of December 31, 2022, we have access to the full availability of the Revolver. If our consolidated leverage ratio
exceeds 3.75:1.00, we may draw up to $30.0 million without the consent of our lenders. The calculation of the consolidated leverage ratio incorporates the
Adjusted EBITDA-trailing twelve months as follows:

(All amounts in thousands)

Total debt
Finance leases

Total consolidated debt

Adjusted EBITDA-trailing twelve months
Pro forma Adjusted EBITDA including impact of acquisitions 
Other adjustments for covenant calculation 

(2)

(1)

Total Adjusted EBITDA-trailing twelve months for covenant calculation

Consolidated leverage ratio

(3)

December 31, 2022

$

$

$

$

1,053,733 
3,260 
1,056,993 

353,558 
— 
253 
353,811 

2.99 

(1)

(2)

(3)

Covenant calculation allows for the Adjusted EBITDA-trailing twelve months to include the impact of acquisitions on a pro forma basis.
Covenant calculation excludes activity at legal entities above the operating company, which is mainly interest income offset by public company
operating expenses.
Calculated by dividing Total consolidated debt by Total Adjusted EBITDA-trailing twelve months for covenant calculation.

66

 
 
 
Results of Operations for the Years Ended December 31, 2022 and 2021

This section of this Form 10-K generally discusses 2022 and 2021 items and year-to-year comparisons between 2022 and 2021. Discussions of 2020
items and year-to-year comparisons between 2021 and 2020 that are not included in this Form 10-K can be found in “Management’s Discussion and Analysis of
Financial Condition and Results of Operations” in Part II, Item 7 of our Annual Report on Form 10-K for the fiscal year ended December 31, 2021, which is
incorporated by reference herein.

Sales

(In thousands except per ton data)

Sales:

Oil & Gas Proppants
Industrial & Specialty Products

Total sales

Tons:

Oil & Gas Proppants
Industrial & Specialty Products

Total Tons

Average Selling Price per Ton:
Oil & Gas Proppants
Industrial & Specialty Products

         Overall Average Selling Price per Ton

Year ended December 31,

2022

2021

Percent Change

2022 vs. 2021

$

$

$

$

961,667  $
563,480 
1,525,147  $

615,448 
488,431 
1,103,879 

13,654 
4,362 
18,016 

70.43  $

129.18 

84.66  $

11,610 
4,227 
15,837 

53.01 
115.55 
69.70 

56 %
15 %
38 %

18 %
3 %
14 %

33 %
12 %
21 %

    Total sales increased 38% for the year ended December 31, 2022 compared to the year ended December 31, 2021, driven by a 14% increase in total tons sold
and a 21% increase in overall average selling price.

    The increase in total sales was mainly driven by Oil & Gas Proppants sales, which increased 56% for the year ended December 31, 2022 compared to the
year ended December 31, 2021. Oil & Gas Proppants average selling price increased 33% and tons sold increased 18%. This overall increase is due to higher
energy prices and a rebound in overall well completion activity, offset partially by the recognition of approximately $49.0 million of shortfall fees during the
second quarter of 2021 which did not recur in 2022.

    The increase in total sales was also partially driven by Industrial & Specialty Products sales, which increased 15% for the year ended December 31, 2022
compared to the year ended December 31, 2021. Industrial & Specialty Products average selling price increased 12% and tons sold increased 3%. The increase
is due to overall improved market conditions and pricing increases implemented throughout the year to help offset increased costs as discussed below.

    Cost of Sales (excluding depreciation, depletion and amortization)

    Cost of sales increased by $275.2 million, or 35%, to $1.1 billion for the year ended December 31, 2022 compared to $795.0 million for the year ended
December 31, 2021. These changes result from the main components of cost of sales as discussed below. As a percentage of sales, cost of sales represented 70%
for the year ended December 31, 2022 compared to 72% for the same period in 2021.

    We incurred $509.8 million and $351.6 million of transportation and related costs for the years ended December 31, 2022 and 2021, respectively. The
increase was mainly due to increased volumes, increased carrier costs for SandBox and increased rail car and barge rates. As a percentage of sales,
transportation and related costs increased to 33% for the year ended December 31, 2022 compared to 32% for the same period in 2021.

    We incurred $171.0 million and $148.0 million of operating labor costs for the years ended December 31, 2022 and 2021, respectively. The $23.0 million
increase in labor costs incurred was mainly due to increased headcount to support increased production and merit increases. As a percentage of sales, operating
labor costs represented 11% for the year ended December 31, 2022 compared to 13% for the same period in 2021.

67

 
    We incurred $83.8 million and $56.2 million of electricity and drying fuel (principally natural gas) costs for the years ended December 31, 2022 and 2021,
respectively. The $27.6 million increase in electricity and drying fuel costs incurred was mainly due to increased volumes produced and increased natural gas
prices. As a percentage of sales, electricity and drying fuel costs represented 5% for both the years ended December 31, 2022 and 2021.

    We incurred $93.8 million and $66.0 million of maintenance and repair costs for the years ended December 31, 2022 and 2021, respectively. The increase in
maintenance and repair costs incurred was mainly due to an increase in maintenance projects as production increased. As a percentage of sales, maintenance
and repair costs represented 6% for both the years ended December 31, 2022 and 2021.

    Segment Contribution Margin

    Oil & Gas Proppants contribution margin increased by $141.7 million to $301.8 million for the year ended December 31, 2022 compared to $160.1 million
for the year ended December 31, 2021, driven by a $346.2 million increase in sales, partially offset by $204.4 million in increased cost of sales. The increase in
segment contribution margin was mainly driven by increased production and pricing, overall improved market conditions, and a rebound in well completion
activity.

    Industrial & Specialty Products contribution margin increased by $1.8 million, or 1%, to $170.3 million for the year ended December 31, 2022 compared to
$168.5 million for the year ended December 31, 2021, driven by a $75.0 million increase in revenue, partially offset by $73.3 million in increased cost of sales.
The increase in segment contribution margin was due to overall improved market conditions and price increases implemented throughout the year, partially
offset by cost increases as discussed above.    

Selling, General and Administrative Expenses

    Selling, general and administrative expenses increased by $24.2 million, or 20%, to $143.8 million for the year ended December 31, 2022 compared to
$119.6 million for the year ended December 31, 2021. The increase was primarily due to fees related to the termination of a supplier contract, increased legal
expenses, increases in compensation such as merit and incentive increases, headcount increases due to increased business activity, and expenses related to the
strategic review of our ISP segment. In total, our selling, general and administrative expenses represented approximately 9% and 11% of our sales for the years
ended December 31, 2022 and 2021, respectively.

    Depreciation, Depletion and Amortization

    Depreciation, depletion and amortization expense decreased by $20.9 million, or 13%, to $140.2 million for the year ended December 31, 2022 compared to
$161.1 million for the year ended December 31, 2021. The decrease was primarily due to certain assets fully depreciating at the end of 2021 and continuing
throughout 2022. Depreciation, depletion and amortization expense represented approximately 9% and 15% of our sales for the years ended December 31, 2022
and 2021, respectively.

Goodwill and Other Asset Impairments

    During the year ended December 31, 2022, no impairment charges were recorded. During the year ended December 31, 2021, we recorded $0.2 million in
asset impairment charges.

Operating Income (Loss)

    Operating income was $171.0 million for the year ended December 31, 2022 compared to operating income of $27.9 million for the year ended
December 31, 2021. The increase was driven by a 38% increase in total sales, a 13% decrease in depreciation, depletion and amortization expense, partially
offset by a 35% increase in cost of sales, and a 20% increase in selling, general and administrative expense.

    Interest Expense

    Interest expense increased by $6.4 million, or 9%, to $77.6 million for the year ended December 31, 2022 compared to $71.2 million for the year ended
December 31, 2021, primarily due to higher interest rates.

    Other Income (Expense), net, including interest income

    Other income increased by $4.5 million to $10.6 million for the year ended December 31, 2022 compared to $6.1 million in other income for the year ended
December 31, 2021. The increase is primarily due to a gain on extinguishment of debt during 2022 and an adjustment in non-service pension costs.

68

    Provision for Income Taxes    

    We had income tax expense of $26.2 million for the year ended December 31, 2022 compared to income tax benefit of $2.8 million for the year ended
December 31, 2021. The effective tax rates were 25% and 7% for the years ended December 31, 2022 and 2021, respectively. See Note S - Income Taxes to our
Consolidated Financial Statements in Part II, Item 8. of this Annual Report on Form 10-K for more information.

    Net income (loss)

    Net income (loss) attributable to U.S. Silica Holdings, Inc., was net income of $78.2 million and net loss of $33.8 million for the years ended December 31,
2022 and 2021, respectively. The year over year changes were due to the factors noted above.

69

Liquidity and Capital Resources

This section of this Annual Report on Form 10-K generally discusses 2022 and 2021 items and year-to-year comparisons between 2022 and 2021.
Discussions of 2020 items and year-to-year comparisons between 2021 and 2020 that are not included in this Form 10-K can be found in “Management’s
Discussion and Analysis of Financial Condition and Liquidity and Capital Resources” in Part II, Item 7 of our Annual Report on Form 10-K for the fiscal year
ended December 31, 2021, which is incorporated by reference herein.

Overview

    Our principal liquidity requirements have historically been to service our debt, to meet our working capital, capital expenditure and mine development
expenditure needs, to return cash to our stockholders, and to pay for acquisitions. We have historically met our liquidity and capital investment needs with funds
generated through operations. We have historically funded our acquisitions through cash on hand, borrowings under our credit facilities, or equity issuances.
Our working capital is the amount by which current assets exceed current liabilities and is a measure of our ability to pay our liabilities as they become due. As
of December 31, 2022, our working capital was $385.3 million and we had $78.5 million of availability under the Revolver. Based on our consolidated leverage
ratio of 2.99:1.00 as of December 31, 2022, we have access to the full availability of the Revolver. If our consolidated leverage ratio exceeds 3.75:1.00, we may
draw up to $30.0 million without the consent of our lenders.

     In connection with the EPM acquisition, on May 1, 2018, we entered into the Credit Agreement with BNP Paribas, as administrative agent, and the lenders
named therein. The Credit Agreement increased our existing senior debt by creating a new $1.380 billion senior secured Credit Facility, consisting of a $1.280
billion Term Loan and a $100 million Revolver that may also be used for swingline loans or letters of credit, and we may elect to increase the Term Loan in
accordance with the terms of the Credit Agreement. The amounts owed under the Credit Agreement use LIBOR as a benchmark for establishing the rate at
which interest accrues. We have made significant progress to prepare for the phasing out of LIBOR and additional transition efforts to prepare for the phasing
out of LIBOR are ongoing. We believe both the enacted and proposed regulations help provide clarity for the transition of our legacy LIBOR contracts,
including investment securities and loans, to alternative reference rates in an orderly manner.

    Management and our Board remain committed to evaluating additional ways of creating shareholder value. Any determination to pay dividends or other
distributions in cash, stock, or property in the future or otherwise return capital to our stockholders, including decisions about existing or new share repurchase
programs, will be at the discretion of our Board and will be dependent on then-existing conditions, including industry and market conditions, our financial
condition, results of operations, liquidity and capital requirements, contractual restrictions including restrictive covenants contained in debt agreements, and
other factors. Additionally, because we are a holding company, our ability to pay dividends on our common stock may be limited by restrictions on the ability of
our subsidiaries to pay dividends or make distributions to us, including restrictions under the terms of the agreements governing our indebtedness. During 2020,
our Board of Directors determined that it was not in the best interest of our shareholders to issue a dividend subsequent to the second quarter of the year. We do
not have plans to resume issuing dividends.

Net Debt (non-GAAP measure)

Net debt is a non-GAAP measure and is included in this report because we believe net debt is meaningful to investors as we consider net debt and its

components to be important indicators of liquidity and financial position. Net debt may not be computed the same as similarly titled measures used by other
companies. We define net debt as total debt less cash and cash equivalents. Net debt should not be considered as an alternative or superior to other performance
measures derived in accordance with GAAP. The following table provides net debt (in thousands):

Total Debt
Less:
   Cash and cash equivalents

Net Debt

$

$

December 31, 2022

December 31, 2021

1,056,993  $

280,845 
776,148  $

1,211,420 

239,425 
971,995 

70

Total Debt:

Total debt was $1.06 billion and $1.21 billion as of December 31, 2022 and 2021, respectively. The decrease was primarily due to the repurchase of

$150.0 million of debt and principal payments on the Term Loan.

Cash and Cash Equivalents:

Cash and cash equivalents were $280.8 million and $239.4 million as of December 31, 2022 and 2021, respectively. The increase was primarily due to

receipt of $27.4 million capacity reservation fees from customers, an increase in business operations and collections and an increase in days payable
outstanding.

Cash Flow Analysis

    A summary of operating, investing and financing activities (in thousands) is shown in the following table:

Net cash provided by (used in):

Operating activities
Investing activities
Financing activities

    Net Cash Provided by / Used in Operating Activities

Year ended December 31,

2022

2021

2020

$

262,716  $
(50,953)
(170,343)

169,347  $
(29,856)
(50,986)

(3,403)
(27,564)
(3,853)

    Operating activities consist primarily of net income adjusted for certain non-cash and working capital items. Adjustments to net income for non-cash items
include depreciation, depletion and amortization, deferred revenue, deferred income taxes, equity-based compensation and allowance for credit losses. In
addition, operating cash flows include the effect of changes in operating assets and liabilities, principally accounts receivable, inventories, prepaid expenses and
other current assets, income taxes payable and receivable, accounts payable and accrued liabilities.

    Net cash provided by operating activities was $262.7 million for the year ended December 31, 2022. This was mainly due to $77.8 million of net income
adjusted for non-cash items, including $140.2 million in depreciation, depletion and amortization, $20.9 million in deferred income taxes, $18.4 million in
equity-based compensation, $15.8 million in deferred revenue, $1.0 million related to the gain on sales of property, plant and equipment, and $18.4 million in
other miscellaneous non-cash items. Also contributing to the change was an $8.1 million increase in accounts receivable, a $31.2 million increase in
inventories, a $6.3 million decrease in prepaid expenses and other current assets, a $1.1 million decrease in income taxes, a $67.6 million increase in accounts
payable and accrued liabilities, a $22.4 million decrease in operating lease liabilities, and $7.2 million in other operating assets and liabilities.

    Net Cash Used in / Provided by Investing Activities

    Investing activities consist primarily of cash consideration paid for capital expenditures for growth and maintenance.

    Net cash used in investing activities was $51.0 million for the year ended December 31, 2022. This was mainly due to capital expenditures of $53.2 million
and capitalized intellectual property costs of $0.4 million, partially offset by proceeds from the sale of property, plant and equipment of $2.6 million. Capital
expenditures for the year ended December 31, 2022 were primarily related to facility improvement and maintenance projects, growth projects, equipment lease
buyouts and other environmental and health and safety projects.

    Subject to our continuing evaluation of market conditions, we anticipate that our capital expenditures in 2023 will be in the range of approximately
$50 million to $60 million, which is primarily associated with maintenance, cost improvement capital projects and various growth projects. We expect to fund
our capital expenditures through cash on our balance sheet and cash generated from our operations.

    Net Cash Used in / Provided by Financing Activities

    Financing activities consist primarily of equity issuances, borrowings and repayments related to the Revolver and Term Loan, as well as fees and expenses
paid in connection with our credit facilities.

    Net cash used in financing activities was $170.3 million for the year ended December 31, 2022. This was mainly due to $158.1 million of long-term debt
payments, which included $145.1 million in debt repurchases, $7.2 million of short term

71

 
 
debt payments, $3.0 million of tax payments related to shares withheld for vested restricted stock and stock units, $1.4 million principal payments on finance
lease obligations, and a $1.5 million distribution to a non-controlling interest, partially offset by proceeds from options exercised of $1.0 million.

Share Repurchase Program

We did not make any repurchases of our common stock under our stock repurchase program in 2022. See Purchase of Equity Securities by the Issuer in

Part II, Item 5. to our Consolidated Financial Statements in Part II, Item 8. of this Annual Report on Form 10-K for information related to our share repurchase
program.

Credit Facilities

See Note K - Debt to our Consolidated Financial Statements in Part II, Item 8. of this Annual Report on Form 10-K for information related to our credit

facilities.

Off-Balance Sheet Arrangements

    We have no off-balance sheet arrangements that have a current material effect or are reasonably likely to have a future material effect on our financial
condition, changes in financial condition, sales, expenses, results of operations, liquidity, capital expenditures or capital resources.

72

Contractual Obligations

As of December 31, 2022, the total of our future contractual cash commitments, including the repayment of our debt obligations under the Term Loan, is

summarized as follows:

(1)

Principal payments on long-term debt
Estimated interest payments on long-term debt
Retirement plans
Finance lease obligations 
Operating lease obligations
Minimum purchase obligations

(5)

(5)

(2)

(4)

(3)
Total Contractual Cash Obligations :

Total

Less than
1 year

1-3 years

3-5 years

(amounts in thousands)

More than
5 years

$

$

1,059,062  $
201,827 
97,087 
3,518 
103,456 
29,331 
1,494,281  $

12,800  $
98,087 
10,600 
1,249 
24,707 
10,606 
158,049  $

1,046,262  $
103,740 
20,802 
1,965 
34,955 
7,181 
1,214,905  $

—  $
— 
20,065 
304 
20,093 
4,060 
44,522  $

— 
— 
45,620 
— 
23,701 
7,484 
76,805 

(1)
(2)

(3)

(4)
(5)

Excludes the unamortized debt issuance costs and original issue discount.
Includes estimated future minimum purchase obligations related to transload service agreements and transportation service agreements. As of
December 31, 2022, we accrued $0.3 million in shortfall fees under these service agreements.
The above table excludes discounted asset retirement obligations in the amount of $20.7 million at December 31, 2022, the majority of which have a
settlement date beyond 2026, as well as indemnification for surety bonds issued on our behalf discussed in Note P - Commitments and Contingencies
to our Consolidated Financial Statements in Part II, Item 8 of this Annual Report on Form 10-K.
Estimated interest payment amounts are computed using forecasted three-month LIBOR rates as of December 31, 2022.
Includes interest and other operating costs. See Note R - Leases to our Consolidated Financial Statements in Part II, Item 8 of this Annual Report on
Form 10-K for additional information on interest costs.

Environmental Matters

We are subject to various federal, state and local laws and regulations governing, among other things, hazardous materials, air and water emissions,

environmental contamination and reclamation and the protection of the environment and natural resources. We have made, and expect to make in the future,
expenditures to comply with such laws and regulations, but we cannot estimate or predict the full amount of such future expenditures. As of December 31,
2022, we had $20.7 million accrued for future reclamation costs, as compared to $32.0 million as of December 31, 2021.

We discuss certain environmental matters relating to our various production and other facilities, certain regulatory requirements relating to human
exposure to crystalline silica and our mining activity and how such matters may affect our business in the future under Item 1. Business, Item 1A. Risk Factors
and Item 3. Legal Proceedings of this Annual Report on Form 10-K.

Critical Accounting Policies and Estimates

Our discussion and analysis of our financial condition and results of operations are based upon our consolidated financial statements, which have been

prepared in accordance with accounting principles generally accepted in the United States of America. The preparation of these financial statements requires us
to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the dates of
the financial statements and the reported revenues and expenses during the reporting periods. We evaluate these estimates and assumptions on an ongoing basis
and base our estimates on historical experience, current conditions and various other assumptions that are believed to be reasonable under the circumstances.
The results of these estimates form the basis for making judgments about the carrying values of assets and liabilities as well as identifying and assessing the
accounting treatment with respect to commitments and contingencies. Our actual results may materially differ from these estimates.

A summary of our significant accounting policies is included in Note B - Summary of Significant Accounting Policies to the Consolidated Financial

Statements in Item 8. of this Annual Report on Form 10-K. Management believes that the application of these policies on a consistent basis enables us to
provide the users of the Consolidated Financial Statements with useful and reliable information about our operating results and financial condition.

73

 
 
 
Described below are the accounting policies we believe are critical to our financial statements due to the degree of uncertainty regarding the estimates or

assumptions involved, and that we believe are critical to the understanding of our operations and our performance.

Revenue Recognition

Products

We derive our product sales by mining and processing minerals that our customers purchase for various uses. Our product sales are primarily a function

of the price per ton and the number of tons sold. We primarily sell our products through individual purchase orders executed under short-term price agreements
or at prevailing market rates. The amount invoiced reflects product, transportation and additional handling services as applicable, such as storage, transloading
the product from railcars to trucks and last mile logistics to the customer site. We invoice most of our product customers on a per shipment basis, although for
some larger customers, we consolidate invoices weekly or monthly. Standard collection terms are net 30 days, although extended terms are offered in
competitive situations.

We recognize revenue for products and materials at a point in time following the transfer of control of such items to the customer, which typically occurs
upon shipment or delivery depending on the terms of the underlying contracts. We account for shipping and handling activities related to product and material
sales contracts with customers as costs to fulfill our promise to transfer the associated products pursuant to the accounting policy election allowed under ASC
606-10-25-10b. Accordingly, we record amounts billed for shipping and handling costs as a component of net sales and accrue and classify related costs as a
component of cost of sales at the time revenue is recognized.

For a limited number of customers, we sell under long-term, minimum purchase supply agreements. These agreements define, among other commitments,

the volume of product that our customers must purchase, the volume of product that we must provide and the price that we will charge and that our customers
will pay for each product. Prices under these agreements are generally fixed and subject to certain contractual adjustments. Sometimes these agreements may
undergo negotiations regarding pricing and volume requirements, which may often occur in volatile market conditions. While these negotiations continue, we
may deliver sand at prices or at volumes below the requirements in our existing supply agreements. An executed order specifying the type and quantity of
product to be delivered, in combination with the noted agreements, comprise our contracts in these arrangements.

Service

We derive our service revenues primarily through the provision of transportation, equipment rental, and contract labor services to companies in the oil and
gas industry. Transportation services typically consist of transporting customer proppant from storage facilities to proximal well-sites and are contracted through
work orders executed under established pricing agreements. The amount invoiced reflects the transportation services rendered. Equipment rental services
provide customers with use of either dedicated or nonspecific wellhead proppant delivery equipment solutions for contractual periods defined either through
formal lease agreements or executed work orders under established pricing agreements. The amounts invoiced reflect the length of time the equipment set was
utilized in the billing period. Contract labor services provide customers with proppant delivery equipment operators through work orders executed under
established pricing agreements. The amounts invoiced reflect the amount of time our labor services were utilized in the billing period.

We typically invoice our customers on a weekly or monthly basis; however, some customers receive invoices upon well-site operation completion.
Standard collection terms are net 30 days, although extended terms are offered in competitive situations. We typically recognize revenue for specific, dedicated
equipment set rental arrangements under ASC 842, Leases. For the remaining components of service revenue, we have applied the practical expedient allowed
under ASC 606-10-55-18 to recognize transportation revenues in proportion to the amount we have the right to invoice.

Contracts with Multiple Performance Obligations

From time to time, we may enter into contracts that contain multiple performance obligations, such as work orders containing a combination of product,

transportation, equipment rentals, and contract labor services. For these arrangements, we allocate the transaction price to each performance obligation
identified in the contract based on relative standalone selling prices, or estimates of such prices, and recognize the related revenue as control of each individual
product or service is transferred to the customer, in satisfaction of the corresponding performance obligations. We typically invoice our customers on a weekly
or monthly basis; however, some customers received invoices upon well-site operation completion. Standard collection terms are net 30 days, although
extended terms are offered in competitive situations.

74

Taxes Collected from Customers and Remitted to Governmental Authorities 

We exclude from our measurement of transaction prices all taxes assessed by governmental authorities that are both (i) imposed on and concurrent with a
specific revenue-producing transaction and (ii) collected from customers. Accordingly, such tax amounts are not included as a component of net sales or cost of
sales.

Deferred Revenues

For a limited number of customers, we enter into supply agreements which give customers the right to make advanced payments toward the purchase of

certain products at specified volumes over an average initial period of one to fifteen years. These payments represent consideration that is unconditional and for
which we have yet to transfer the related product. These payments are recorded as contract liabilities referred to as “deferred revenues” upon receipt and
recognized as revenue upon delivery of the related product.

Unbilled Receivables

Revenues recognized in advance of invoice issuance create assets referred to as “unbilled receivables.” Any portion of our unbilled receivables for which
our right to consideration is conditional on a factor other than the passage of time is considered a contract asset. These assets are presented on a combined basis
with accounts receivable and are converted to accounts receivable once billed.

Impairment or Disposal of Property, Plant and Mine Development

We periodically evaluate whether current events or circumstances indicate that the carrying value of our property, plant and equipment assets may not be
recoverable. If circumstances indicate that the carrying value may not be recoverable, we estimate future undiscounted net cash flows using estimates of proven
and probable sand reserves, estimated future sales prices (considering historical and current prices, price trends and related factors) and operating costs and
anticipated capital expenditures. If the undiscounted cash flows are less than the carrying value of the assets, we recognize an impairment loss equal to the
amount by which the carrying value exceeds the fair value of the assets.

The recoverability of the carrying value of our mineral properties is dependent upon the successful development, start-up and commercial production of

our mineral deposit and the related processing facilities. Our evaluation of mineral properties for potential impairment primarily includes assessing the
existence or availability of required permits and evaluating changes in our mineral reserves, or the underlying estimates and assumptions, including estimated
production costs. Assessing the economic feasibility requires certain estimates including the prices of products to be produced and processing recovery rates, as
well as operating and capital costs.

Gains on the sale of property, plant and mine development are included in income when the assets are disposed of provided there is more than reasonable

certainty of the collectability of the sales price and any future activities required to be performed by us relating to the disposal of the assets are complete or
insignificant. Upon retirement or disposal of assets all costs and related accumulated depreciation or amortization are written-off.

Goodwill and Other Intangible Assets and Related Impairment

Our intangible assets consist of goodwill, which is not amortized, indefinite-lived intangibles, which consist of certain trade names that are not subject to

amortization, intellectual property and customer relationships.

Intellectual property mainly consists of patents and technology, and it is amortized on a straight-line basis over an average useful life of 15 years.

Customer relationships are amortized on a straight-line basis over their useful life of 13 - 20 years.

Goodwill represents the excess of the purchase price of business combinations over the fair value of net assets acquired. Goodwill and trade names are

reviewed for impairment annually as of October 31, or more frequently when indicators of impairment exist. An impairment exists if the fair value of a
reporting unit to which goodwill has been allocated, or the fair value of indefinite-lived intangible assets, is less than their respective carrying values. Prior to
conducting a formal impairment test, we have an option to assess qualitative factors to determine whether the existence of events or circumstances leads to a
determination that is more likely than not (more than 50%) that the fair value of a reporting unit is less than its carrying amount. Such qualitative factors may
include the following: macroeconomic conditions; industry and market considerations; cost factors; overall financial performance; and other relevant entity-
specific events. If the qualitative assessment determines that an impairment is more likely than not, or if we choose to bypass the qualitative assessment, we
perform a quantitative assessment

75

by comparing the fair value of a reporting unit with its carrying amount and recognize an impairment charge for the amount by which the carrying amount
exceeds the reporting unit’s fair value; however the loss recognized should not exceed the total amount of goodwill allocated to that reporting unit.

A trade name is a legally protected trade or similar mark. Acquired trade names are valued using an income method approach, generally the relief-from-

royalty valuation method. The method uses a royalty rate based on comparable marketplace royalty agreements for similar types of trade names and applies it to
the after-tax discounted free cash flow attributed to the trade name. The discount rate used is based on an estimated weighted average cost of capital and the
anticipated risk for intangible assets. The valued trade names have an indefinite life based on our plans and expectations for the trade names going forward and
are reviewed for impairment annually, or more frequently when indicators of impairment exist.

Intellectual property and technology (“IP”) is a design, work or invention that is the result of creativity to which one has ownership rights that may be
protected through a patent, copyright, trademark or service mark. IP is valued using the relief-from-royalty valuation method. The method uses a royalty rate
based on comparable marketplace royalty agreements for similar types of IP and applies it to the after-tax discounted free cash flow attributed to the IP. The
discount rate used is based on an estimated weighted average cost of capital and the anticipated risk for intangible assets. The IP is amortized following the
pattern in which the expected benefits will be consumed or otherwise used up over each component’s useful life, based on our plans and expectations for the IP
going forward, which is generally the underlying IP’s legal expiration dates. IP is reviewed for impairment annually, or more frequently when indicators of
impairment exist.

Customer relationships are intangible assets that consist of historical and factual information about customers and contacts collected from repeat

transactions with customers, with or without any underlying contracts. The information is generally organized as customer lists or customer databases. We have
the expectation of repeat patronage from these customers based on the customers’ historical purchase activity, which creates the intrinsic value over a finite
period of time and translates into the expectation of future revenue, income, and cash flow. Customer relationships are valued using projected operating income,
adjusted for estimated future existing customer growth less estimated future customer attrition, net of charges for net tangible assets, IP charge, trade name
charge and work force. The concluded value is the after-tax discounted free cash flow. Customer relationships are reviewed for impairment annually, or more
frequently when indicators of impairment exist.

Income Taxes

Deferred taxes are recognized on the liability method whereby deferred tax assets are recognized for deductible temporary differences and operating loss

and tax credit carry forwards and deferred tax liabilities are recognized for taxable temporary differences. This approach requires recognition of deferred tax
liabilities and assets for the expected future tax consequences of events that have been included in the financial statements or tax returns. Under this method,
deferred tax liabilities and assets are determined based upon the difference between the financial statement and tax basis of assets and liabilities using enacted
tax rates in effect for the year in which the expenses are expected to reverse. Valuation allowances are provided if, based on the weight of available evidence, it
is more likely than not that some or all of the deferred tax assets will not be realized.

We recognize a tax benefit associated with an uncertain tax position when, in management’s judgment, it is more likely than not that the position will be

sustained upon examination by a taxing authority. For a tax position that meets the more-likely-than-not recognition threshold, we initially and subsequently
measure the tax benefit as the largest amount that we judge to have a greater than 50% likelihood of being realized upon ultimate settlement with a taxing
authority. The liability associated with unrecognized tax benefits is adjusted periodically due to changing circumstances, such as the progress of tax audits, case
law developments and new or emerging legislation. Such adjustments are recognized entirely in the period in which they are identified. The effective tax rate
includes the net impact of changes in the liability for unrecognized tax benefits and subsequent adjustments as considered appropriate by management.

Recent Accounting Pronouncements

New accounting guidance that has been recently issued is described in Note B - Summary of Significant Accounting Policies to our Consolidated

Financial Statements in Part II, Item 8 of this Annual Report on Form 10-K.

76

ITEM 7A.

QUANTITATIVE AND QUALITATIVE DISCLOSURES ABOUT MARKET RISK

Market Risk

We are exposed to certain market risks, which exist as a part of our ongoing business operations. Such risks arise from adverse changes in market rates,
prices and conditions. We address such market risks in “Recent Trends and Outlook” and "How We Generate Our Sales" in Item 7. Management's Discussion
and Analysis of Financial Condition and Results of Operations of this Annual Report on Form 10-K.

Interest Rate Risk

We are exposed to interest rate risk arising from adverse changes in interest rates. As of December 31, 2022, we had $1.06 billion of debt outstanding
under the Credit Agreement. Assuming LIBOR is greater than the 1.0% minimum base rate on the Term Loan, a hypothetical increase in interest rates by 1.0%
would have changed our interest expense by $10.6 million per year.

We have made significant progress to prepare for the phasing out of LIBOR and additional transition efforts to prepare for the phasing out of LIBOR are

ongoing.

On March 15, 2022, President Biden signed the Consolidated Appropriation Act of 2022 into law, which includes the Adjustable Interest Rate (LIBOR)

Act, containing legislation related to the transition away from LIBOR. This legislation is intended to establish a uniform process for replacing LIBOR in
existing contracts and securities that continue after the cessation of LIBOR and do not contain clearly defined or practicable fallback provisions.

On July 19, 2022, the Federal Reserve Board released a proposal that provides default rules for certain contracts that use LIBOR, which would implement

the LIBOR Act with replacement rates based on the Secured Overnight Financing Rate (SOFR). We believe the LIBOR Act and the Federal Reserve Board's
proposed regulation help provide clarity for the transition of our legacy LIBOR contracts, including investment securities and loans, to alternative reference
rates in an orderly manner.

Credit Risk

We are subject to risks of loss resulting from nonpayment or nonperformance by our customers. We examine the creditworthiness of third-party customers

to whom we extend credit and manage our exposure to credit risk through credit analysis, credit approval, credit limits and monitoring procedures, and for
certain transactions, we may request letters of credit, prepayments or guarantees, although collateral is generally not required.

Despite enhancing our examination of our customers' creditworthiness, we may still experience delays or failures in customer payments. Some of our
customers have reported experiencing financial difficulties. With respect to customers that may file for bankruptcy protection, we may not be able to collect
sums owed to us by these customers and we also may be required to refund pre-petition amounts paid to us during the preference period (typically 90 days)
prior to the bankruptcy filing.

77

ITEM 8.

FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA

The following Consolidated Financial Statements are filed as part of this Annual Report on Form 10-K:

U.S. SILICA HOLDINGS, INC.

Report of Independent Registered Public Accounting Firm (PCAOB ID Number 248)
Consolidated Balance Sheets as of December 31, 2022 and 2021
Consolidated Statements of Operations for the Years Ended December 31, 2022, 2021 and 2020
Consolidated Statements of Comprehensive Income for the Years Ended December 31, 2022, 2021 and 2020
Consolidated Statements of Stockholders’ Equity for the Years Ended December 31, 2022, 2021 and 2020
Consolidated Statements of Cash Flows for the Years Ended December 31, 2022, 2021 and 2020
Notes to the Consolidated Financial Statements

78

79
80
81
82
83
85
87

REPORT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

Board of Directors and Shareholders
U.S. Silica Holdings, Inc.

Opinion on the financial statements
We have audited the accompanying consolidated balance sheets of U.S. Silica Holdings, Inc. (a Delaware corporation) and subsidiaries (the “Company”) as of
December 31, 2022 and 2021, the related consolidated statements of operations, comprehensive income, shareholders’ equity, and cash flows for each of the
three years in the period ended December 31, 2022, and the related notes and financial statement schedule (collectively referred to as the “financial
statements”). In our opinion, the financial statements present fairly, in all material respects, the financial position of the Company as of December 31, 2022 and
2021, and the results of its operations and its cash flows for each of the three years in the period ended December 31, 2022, in conformity with accounting
principles generally accepted in the United States of America.

We also have audited, in accordance with the standards of the Public Company Accounting Oversight Board (United States) (“PCAOB”), the Company’s
internal control over financial reporting as of December 31, 2022, based on criteria established in the 2013 Internal Control—Integrated Framework issued by
the Committee of Sponsoring Organizations of the Treadway Commission (“COSO”), and our report dated February 24, 2023 expressed an unqualified opinion.

Basis for opinion
These financial statements are the responsibility of the Company’s management. Our responsibility is to express an opinion on the Company’s financial
statements based on our audits. We are a public accounting firm registered with the PCAOB and are required to be independent with respect to the Company in
accordance with the U.S. federal securities laws and the applicable rules and regulations of the Securities and Exchange Commission and the PCAOB.

We conducted our audits in accordance with the standards of the PCAOB. Those standards require that we plan and perform the audit to obtain reasonable
assurance about whether the financial statements are free of material misstatement, whether due to error or fraud. Our audits included performing procedures to
assess the risks of material misstatement of the financial statements, whether due to error or fraud, and performing procedures that respond to those risks. Such
procedures included examining, on a test basis, evidence regarding the amounts and disclosures in the financial statements. Our audits also included evaluating
the accounting principles used and significant estimates made by management, as well as evaluating the overall presentation of the financial statements. We
believe that our audits provide a reasonable basis for our opinion.

Critical audit matters
Critical audit matters are matters arising from the current period audit of the financial statements that were communicated or required to be communicated to
the audit committee and that: (1) relate to accounts or disclosures that are material to the financial statements and (2) involved our especially challenging,
subjective, or complex judgements. We determined that there are no critical audit matters.

/s/ GRANT THORNTON LLP

We have served as the Company’s auditor since 2004.

Houston, Texas
February 24, 2023

79

U.S. SILICA HOLDINGS, INC.

CONSOLIDATED BALANCE SHEETS

(in thousands, except share data)

ASSETS

LIABILITIES AND STOCKHOLDERS’ EQUITY

Current Assets:

Cash and cash equivalents
Accounts receivable, net
Inventories, net
Prepaid expenses and other current assets

Total current assets

Property, plant and mine development, net
Lease right-of-use assets
Goodwill
Intangible assets, net
Other assets

Total assets

Current Liabilities:

Accounts payable and accrued liabilities
Current portion of operating lease liabilities
Current portion of long-term debt
Current portion of deferred revenue
Income tax payable

Total current liabilities

Long-term debt, net
Deferred revenue
Liability for pension and other post-retirement benefits
Deferred income taxes, net
Operating lease liabilities
Other long-term obligations

Total liabilities

Commitments and Contingencies (Note P)
Stockholders’ Equity:
Preferred stock, $0.01 par value, 10,000,000 shares authorized; zero issued and outstanding at December 31, 2022 and 2021
Common stock, $0.01 par value, 500,000,000 shares authorized; 85,631,109 issued and 75,738,512 outstanding at December 31,
2022; 84,746,194 issued and 75,033,352 outstanding at December 31, 2021
Additional paid-in capital
Retained deficit
Treasury stock, at cost, 9,892,597 and 9,712,842 shares at December 31, 2022 and 2021, respectively
Accumulated other comprehensive income (loss)

Total U.S. Silica Holdings, Inc. stockholders’ equity

Non-controlling interest

Total stockholders' equity

Total liabilities and stockholders’ equity

The accompanying notes are an integral part of these financial statements.

80

December 31,

2022

2021

280,845  $
208,631 
147,626 
20,182 
657,284 
1,178,834 
42,374 
185,649 
140,809 
9,630 
2,214,580  $

216,239  $
19,773 
19,535 
16,275 
128 
271,950 
1,037,458 
14,477 
30,911 
64,636 
64,478 
25,976 
1,509,886 

239,425 
202,759 
115,713 
18,018 
575,915 
1,258,646 
42,241 
185,649 
150,054 
7,095 
2,219,600 

167,670 
14,469 
18,285 
4,247 
1,200 
205,871 
1,193,135 
16,494 
32,935 
44,774 
75,130 
37,178 
1,605,517 

— 

— 

854 
1,234,834 
(351,084)
(186,196)
(1,723)
696,685 
8,009 
704,694 
2,214,580  $

845 
1,218,575 
(429,260)
(186,294)
349 
604,215 
9,868 
614,083 
2,219,600 

$

$

$

$

U.S. SILICA HOLDINGS, INC.

CONSOLIDATED STATEMENTS OF OPERATIONS

(in thousands, except per share amounts)

Sales:

Product
Service

Total sales

Cost of sales (excluding depreciation, depletion and amortization):

Product
Service

Total cost of sales (excluding depreciation, depletion and amortization)

Operating expenses:

Selling, general and administrative
Depreciation, depletion and amortization
Goodwill and other asset impairments

Total operating expenses

Operating income (loss)

Other (expense) income:
Interest expense
Other income, net, including interest income

Total other expense

Income (loss) before income taxes

Income tax (expense) benefit
Net income (loss)

Less: Net loss attributable to non-controlling interest

Net income (loss) attributable to U.S. Silica Holdings, Inc.

Earnings (loss) per share attributable to U.S. Silica Holdings, Inc.:

Basic
Diluted

Weighted average shares outstanding:

Basic
Diluted

Dividends declared per share

Year Ended 
 December 31,
2021

2022

2020

$

$

$

$
$

$

1,139,773  $
385,374 
1,525,147 

896,203  $
207,676 
1,103,879 

801,789 
268,400 
1,070,189 

143,838 
140,166 
— 
284,004 
170,954 

(77,598)
10,643 
(66,955)
103,999 
(26,159)
77,840  $
(336)
78,176  $

1.04  $
1.01  $

75,512 
77,670 

633,857 
161,126 
794,983 

119,628 
161,131 
202 
280,961 
27,935 

(71,157)
6,146 
(65,011)
(37,076)
2,755 
(34,321) $
(560)
(33,761) $

(0.45) $
(0.45) $

74,350 
74,350 

—  $

—  $

732,187 
113,698 
845,885 

486,982 
88,088 
575,070 

124,171 
155,568 
110,688 
390,427 
(119,612)

(79,885)
24,350 
(55,535)
(175,147)
60,025 
(115,122)
(1,028)
(114,094)

(1.55)
(1.55)

73,634 
73,634 
0.02 

The accompanying notes are an integral part of these financial statements.

81

 
 
 
U.S. SILICA HOLDINGS, INC.

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS)

(in thousands)

Net income (loss)
Other comprehensive (loss) income:

Unrealized (loss) gain on derivatives (net of tax of $(746), $0, and $973 for 2022, 2021, and 2020,
respectively)
Foreign currency translation adjustment (net of tax of $(269), $(309), and $444 for 2022, 2021 and
2020, respectively)
Pension and other post-retirement benefits liability adjustments (net of tax of $355, $3,131, and
$2,207 for 2022, 2021 and 2020, respectively)

Comprehensive income (loss)

Less: Comprehensive loss attributable to non-controlling interest
Comprehensive income (loss) attributable to U.S. Silica Holdings, Inc.

Year Ended 
 December 31,
2021

2022

2020

$

77,840  $

(34,321) $

(115,122)

(2,342)

(845)

1,115 
75,768  $
(336)
76,104  $

— 

(1,000)

9,828 
(25,493) $
(560)
(24,933) $

3,053 

1,391 

6,931 
(103,747)
(1,028)
(102,719)

$

$

The accompanying notes are an integral part of these financial statements.

82

 
 
 
U.S. SILICA HOLDINGS, INC.

CONSOLIDATED STATEMENTS OF STOCKHOLDERS’ EQUITY

(in thousands, except per share amounts)

Balance at January 1, 2020

$

Net loss
Unrealized gain on derivatives
Foreign currency translation
adjustment
Pension and post-retirement
liability
Cash dividend declared ($0.02 per
share)

Contributions from non-
controlling interest
Common stock-based
compensation plans activity:

Equity-based compensation
Shares withheld for tax
payments related to vested
restricted stock and stock units

Balance at December 31, 2020

Net loss
Foreign currency translation
adjustment
Pension and post-retirement
liability
Cash dividends
Distributions to non-controlling
interest
Common stock-based
compensation plans activity:

Equity-based compensation
Proceeds from options
exercised
Shares withheld for tax
payments related to vested
restricted stock and stock units

Balance at December 31, 2021

Net income (loss)

Unrealized loss on derivatives

Foreign currency translation
adjustment
Pension and post-retirement
liability

Common
Stock

823  $
— 
— 

— 

— 

— 

— 

— 

Treasury
Stock
(180,912) $

Additional
Paid-In
Capital

1,185,116  $

— 
— 

— 

— 

— 

— 

— 
— 

— 

— 

— 

— 

— 

14,911 

Retained
Deficit
(279,956) $
(114,094)
— 

— 

— 

(1,446)

— 

— 

4 
827 
— 

(703)
(181,615)
— 

(4)
1,200,023 
— 

— 
(395,496)
(33,761)

— 

— 
— 

— 

— 

— 

18 
845 
— 
— 

— 

— 

— 

— 
— 

— 

— 

344 

— 

— 
— 

— 

18,809 

(239)

— 

— 
(3)

— 

— 

— 

(5,023)
(186,294)
— 
— 

(18)
1,218,575 
— 
— 

— 
(429,260)
78,176 
— 

— 

— 

— 

— 

— 

— 

83

Accumulated
Other
Comprehensive
(Loss) Income

Total U.S. Silica
Holdings Inc.,
Stockholders’
Equity

Non-controlling
Interest

Total
Stockholders’
Equity

(19,854) $

— 
3,053 

1,391 

6,931 

— 

— 

— 

— 
(8,479)
— 

(1,000)

9,828 
— 

— 

— 

— 

— 
349 
— 
(2,342)

(845)

1,115 

705,217  $
(114,094)
3,053 

11,363  $
(1,028)
— 

716,580 
(115,122)
3,053 

1,391 

6,931 

(1,446)

— 

— 

— 

— 

1,196 

1,391 

6,931 

(1,446)

1,196 

14,911 

— 

14,911 

(703)
615,260 
(33,761)

(1,000)

9,828 
(3)

— 
11,531 
(560)

— 

— 
— 

(703)
626,791 
(34,321)

(1,000)

9,828 
(3)

— 

(1,103)

(1,103)

18,809 

105 

(5,023)
604,215 
78,176 
(2,342)

(845)

1,115 

— 

— 

— 
9,868 
(336)
— 

— 

— 

18,809 

105 

(5,023)
614,083 
77,840 
(2,342)

(845)

1,115 

 
 
 
 
 
 
 
 
 
 
 
Cash dividends
Distributions to non-controlling
interest
Common stock-based
compensation plans activity:

Equity-based compensation
Proceeds from options
exercised
Shares withheld for tax
payments related to vested
restricted stock and stock units

Balance at December 31, 2022

$

— 

— 

— 

— 

— 

— 

— 

— 

— 

18,364 

3,051 

(2,096)

— 

— 

— 

— 

— 

— 

— 

— 

— 

— 

— 

18,364 

955 

— 

— 

(1,523)

(1,523)

— 

— 

18,364 

955 

— 
(1,723) $

(2,953)
696,685  $

— 
8,009  $

(2,953)
704,694 

9 
854  $

(2,953)
(186,196) $

(9)

1,234,834  $

(351,084) $

The accompanying notes are an integral part of these financial statements.

84

U.S. SILICA HOLDINGS, INC.

CONSOLIDATED STATEMENTS OF CASH FLOWS

(in thousands)

Operating activities:

Net income (loss)
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating
activities:

Depreciation, depletion and amortization
Goodwill and other asset impairments
Debt issuance amortization
Original issue discount amortization
Gain on valuation change of royalty note payable
Deferred income taxes
Deferred revenue
Gain on disposal of property, plant and equipment
Equity-based compensation
Allowance for credit losses, net of recoveries
Gain on remeasurement of leases
Other

Changes in operating assets and liabilities, net of effects of acquisitions:

Accounts receivable
Inventories
Prepaid expenses and other current assets
Income taxes
Accounts payable and accrued liabilities
Operating lease liabilities
Liability for pension and other post-retirement benefits
Other noncurrent assets and liabilities

Net cash provided by (used in) operating activities

Investing activities:

Capital expenditures
Capitalized intellectual property costs
Proceeds from sale of property, plant and equipment

Net cash used in investing activities

Financing activities:
Dividends paid
Proceeds from options exercised
Tax payments related to shares withheld for vested restricted stock and stock units
(Payments on) proceeds from draw down on the Revolver
Payments on short-term debt
Payments on long-term debt
Distributions to (contributions from) non-controlling interest
Principal payments on finance lease obligations
Net cash used in financing activities
Net increase (decrease) in cash and cash equivalents
Cash and cash equivalents, beginning of period
Cash and cash equivalents, end of period

Year Ended 
 December 31,
2021

2020

2022

$

77,840  $

(34,321) $

(115,122)

140,166 
— 
4,815 
974 
— 
20,940 
(15,801)
(1,005)
18,364 
617 
— 
11,959 

(8,075)
(31,209)
6,277 
(1,072)
67,576 
(22,410)
(2,134)
(5,106)
262,716 

(53,168)
(394)
2,609 
(50,953)

161,131 
202 
5,059 
1,026 
— 
(7,493)
(18,158)
(131)
18,809 
(455)
— 
28,632 

5,026 
(11,029)
12,371 
1,828 
48,709 
(24,451)
(15,341)
(2,067)
169,347 

(30,307)
(210)
661 
(29,856)

(164)
955 
(2,953)
— 
(7,237)
(158,064)
(1,523)
(1,357)
(170,343)
41,420 
239,425 
280,845  $

(26)
105 
(5,023)
(25,000)
(6,398)
(12,800)
(1,103)
(741)
(50,986)
88,505 
150,920 
239,425  $

$

155,568 
110,688 
5,131 
1,036 
(8,263)
(61,805)
(23,569)
(2,597)
14,911 
1,510 
(24,056)
23,146 

48,441 
15,245 
980 
(153)
(86,734)
(62,140)
(11,941)
16,321 
(3,403)

(34,461)
(456)
7,353 
(27,564)

(6,185)
— 
(703)
25,000 
(7,131)
(15,985)
1,196 
(45)
(3,853)
(34,820)
185,740 
150,920 

85

 
 
 
Supplemental cash flow information:
Cash paid (received) during the period for:

Interest
Taxes, net of refunds

Non-cash Items:

Net assets assumed in business acquisition
Accrued capital expenditures

$
$

$
$

71,235  $
(14,809) $

64,650  $
(12,994) $

73,695 
(39,908)

—  $
6,175  $

68  $
1,196  $

8,241 
26,136 

The accompanying notes are an integral part of these financial statements.

86

U.S. SILICA HOLDINGS, INC.

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

NOTE A—ORGANIZATION

U.S. Silica Holdings, Inc. (“Holdings,” and together with its subsidiaries “we,” “us” or the “Company”) is a global performance materials company and a

leading producer of commercial silica used in the oil and gas industry and in a wide range of industrial applications. In addition, through our subsidiary EP
Minerals, LLC ("EPM") we are an industry leader in the production of industrial minerals, including diatomaceous earth, clay (calcium bentonite and calcium
montmorillonite) and perlite. During our 123-year history, we have developed core competencies in mining, processing, logistics and materials science that
enable us to produce and cost-effectively deliver products to customers across our end markets. Our operations are organized into two reportable segments
based on end markets served: (1) Oil & Gas Proppants and (2) Industrial & Specialty Products. See Note V - Segment Reporting for more information on our
reportable segments.

NOTE B—SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

Basis of Presentation and Consolidation

The accompanying Consolidated Financial Statements have been prepared in accordance with generally accepted accounting principles in the United
States (“GAAP”). In the opinion of management, all adjustments necessary for a fair presentation of the Consolidated Financial Statements have been included.
Such adjustments are of a normal, recurring nature.

Throughout this report we refer to (i) our Consolidated Balance Sheets as our “Balance Sheets,” (ii) our Consolidated Statements of Operations as our

“Income Statements,” and (iii) our Consolidated Statements of Cash Flows as our “Cash Flows.”

Consolidation

The Consolidated Financial Statements include the accounts of Holdings and its direct and indirect wholly-owned subsidiaries. All significant

intercompany balances and transactions have been eliminated in consolidation.

Reclassifications

Certain reclassifications of prior period presentations have been made to conform to the current period presentation.

Use of Estimates and Assumptions

The preparation of Consolidated Financial Statements in conformity with GAAP requires management to make estimates and assumptions that affect the
reported amounts of assets and liabilities and the related disclosure of contingent assets and liabilities at the date of the Consolidated Financial Statements and
the reported amounts of revenues and expenses during the reporting period. The areas requiring the use of management estimates and assumptions relate to the
purchase price allocation for businesses acquired; mineral reserves that are the basis for future cash flow estimates utilized in impairment calculations and units-
of-production amortization calculations; environmental, reclamation and closure obligations; estimates of recoverable minerals; estimates of allowance for
credit losses; estimates of fair value for certain reporting units and asset impairments (including impairments of goodwill, intangible assets and other long-lived
assets); write-downs of inventory to net realizable value; equity-based compensation expense; post-employment, post-retirement and other employee benefit
liabilities; valuation allowances for deferred tax assets; contingent considerations; reserves for contingencies and litigation and the fair value and accounting
treatment of financial instruments. We base our estimates on historical experience and on various other assumptions that are believed to be reasonable under the
circumstances. Accordingly, actual results may differ significantly from these estimates under different assumptions or conditions.

Cash and Cash Equivalents

Cash and cash equivalents consist of all highly liquid investments with a maturity of three months or less when purchased. Because of the short maturity

of these investments, the carrying amounts approximate their fair value. Cash and cash equivalents are invested primarily in money market securities held by
financial institutions with high credit ratings. Accounts at each institution are insured by the Federal Deposit Insurance Corporation. Cash balances at times may
exceed federally-insured limits. We have not experienced any losses in such accounts and believe we are not exposed to any significant credit risk on cash.

87

Accounts Receivable

The majority of our accounts receivable are due from companies in the oil and natural gas drilling, building and construction products, filler and

extenders, filtration, glass, absorbents, sports and recreation, foundry and other major industries. Credit is extended based on evaluation of a customer’s
financial condition and, generally, collateral is not required. Accounts receivable are stated at amounts due from customers net of allowance for credit losses.
Accounts outstanding longer than the payment terms are considered past due. We determine our allowance by considering a number of factors, including the
length of time trade accounts receivable are past due, our previous loss history, the customer’s current ability to pay its obligation to us and the condition of the
general economy and the industry as a whole. Ongoing credit evaluations are performed. We write-off accounts receivable when they are deemed uncollectible,
and payments subsequently received on such receivables are credited to the allowance for credit losses. See Note F - Accounts Receivable and Note T -
Revenue.

Inventories

Inventories include raw stockpiles, in-process product and finished product available for shipment, as well as spare parts and supplies for routine facility

maintenance. We value inventory at the lower of cost and net realizable value. Cost is determined using the first-in, first-out and average cost methods. Our
inventoriable costs include production costs and transportation and additional service costs as applicable. See Note G - Inventories.

Property, Plant and Mine Development

Plant and equipment

Plant and equipment is recorded at cost and depreciated over their estimated useful lives. Interest incurred during construction of facilities is capitalized
and depreciated over the life of the asset. Costs for normal repairs and maintenance that do not extend economic life or improve service potential are expensed
as incurred. Costs of improvements that extend economic life or improve service potential are capitalized and depreciated over the estimated remaining useful
life.

Depreciation is recorded using the straight-line method over the assets’ estimated useful lives as follows: buildings (15 years); land improvements (10

years); machinery and equipment, including computer equipment and software (3-10 years); furniture and fixtures (8 years). Leasehold improvements are
depreciated over the shorter of the asset life or lease term. Construction-in-progress is primarily comprised of machinery and equipment which have not yet
been placed in service.

Mining property and development

Mining property and development includes mineral deposits and mine exploration and development. Mineral deposits are initially recognized at cost,

which approximates the estimated fair value on the date of purchase. Mine exploration and development costs include engineering and mineral studies, drilling
and other related costs to delineate an ore body, and the removal of overburden to initially expose an ore body for production. Costs incurred before
mineralization are classified as proven and probable reserves are expensed and classified as exploration or advanced projects, research and development
expense. Capitalization of mine development project costs, which meet the definition of an asset, begins once mineralization is classified as proven and
probable reserves.

The cost of removing overburden and waste materials to access the ore body at an open pit mine prior to the production phase are referred to as “pre-

stripping costs.” Pre-stripping costs are capitalized during the development of an open pit mine. The production phase of an open pit mine commences when
saleable minerals, beyond a de minimis amount, are produced. Stripping costs incurred during the production phase of a mine are variable production costs that
are included as a component of inventory to be recognized in costs applicable to sales in the same period as the revenue from the sale of inventory.

Depletion and amortization of mineral deposits and mine development costs are recorded as the minerals are extracted, based on units of production and

engineering estimates of mineable reserves. The impact of revisions to reserve estimates is recognized on a prospective basis.

See Note H - Property, Plant and Mine Development.

Mine reclamation costs and asset retirement obligations

We recognize the fair value of any liability for conditional asset retirement obligations, if sufficient information exists to reasonably estimate the fair

value of the liability. These obligations include environmental remediation liabilities when incurred, which is generally upon acquisition, construction or
development and/or through the normal operation of the asset. These obligations also generally include the estimated net future costs of dismantling, restoring
and reclaiming operating mines and related mine sites in accordance with federal, state, local regulatory and land lease agreement requirements. The liability is

88

accreted over time through periodic charges to earnings. In addition, the asset retirement cost is capitalized as part of the asset’s carrying value and amortized
over the life of the related asset. Reclamation costs are periodically adjusted to reflect changes in the estimated present value resulting from the passage of time
and revisions to the estimates of either the timing or amount of the reclamation and abandonment costs. The reclamation obligation is based on when spending
for an existing environmental disturbance will occur. If the asset retirement obligation is settled for other than the carrying amount of the liability, a gain or loss
is recognized on settlement. We review, on an annual basis, unless otherwise deemed necessary, the reclamation obligation at each mine site in accordance with
ASC guidance for accounting for reclamation obligations.

See Note L - Asset Retirement Obligations.

Impairment or Disposal of Property, Plant and Mine Development

We periodically evaluate whether current events or circumstances indicate that the carrying value of our property, plant and equipment assets may not be
recoverable. If circumstances indicate that the carrying value may not be recoverable, we estimate future undiscounted net cash flows using estimates of proven
and probable sand reserves, estimated future sales prices (considering historical and current prices, price trends and related factors) and operating costs and
anticipated capital expenditures. If the undiscounted cash flows are less than the carrying value of the assets, we recognize an impairment loss equal to the
amount by which the carrying value exceeds the fair value of the assets.

The recoverability of the carrying value of our mineral properties is dependent upon the successful development, start-up and commercial production of

our mineral deposit and the related processing facilities. Our evaluation of mineral properties for potential impairment primarily includes assessing the
existence or availability of required permits and evaluating changes in our mineral reserves, or the underlying estimates and assumptions, including estimated
production costs. Assessing the economic feasibility requires certain estimates including the prices of products to be produced and processing recovery rates, as
well as operating and capital costs.

Gains on the sale of property, plant and mine development are included in income when the assets are disposed of provided there is more than reasonable

certainty of the collectability of the sales price and any future activities required to be performed by us relating to the disposal of the assets are complete or
insignificant. Upon retirement or disposal of assets, all costs and related accumulated depreciation or amortization are written-off.

Goodwill and Other Intangible Assets and Related Impairment

Our intangible assets consist of goodwill, which is not amortized, indefinite-lived intangibles, which consist of certain trade names that are not subject to
amortization, intellectual property and customer relationships. Intellectual property mainly consists of patents and technology, and it is amortized on a straight-
line basis over an average useful life of 15 years. Customer relationships are amortized on a straight-line basis over their useful life of 13 - 20 years. Intangible
assets that are amortized are reviewed for impairment annually, or more frequently when indicators of impairment exist.

Goodwill represents the excess of the purchase price of business combinations over the fair value of net assets acquired. Goodwill and trade names are

reviewed for impairment annually as of October 31, or more frequently when indicators of impairment exist. An impairment exists if the fair value of a
reporting unit to which goodwill has been allocated, or the fair value of indefinite-lived intangible assets, is less than their respective carrying values. Prior to
conducting a formal impairment test, we have an option to assess qualitative factors to determine whether the existence of events or circumstances leads to a
determination that is more likely than not (more than 50%) that the fair value of a reporting unit is less than its carrying amount. Such qualitative factors may
include the following: macroeconomic conditions; industry and market considerations; cost factors; overall financial performance; and other relevant entity-
specific events. If the qualitative assessment determines that an impairment is more likely than not, or if we choose to bypass the qualitative assessment, we
perform a quantitative assessment by comparing the fair value of a reporting unit with its carrying amount and recognize an impairment charge for the amount
by which the carrying amount exceeds the reporting unit’s fair value; however the loss recognized should not exceed the total amount of goodwill allocated to
that reporting unit.

89

A trade name is a legally protected trade or similar mark. Acquired trade names are valued using an income method approach, generally the relief-from-

royalty valuation method. The method uses a royalty rate based on comparable marketplace royalty agreements for similar types of trade names and applies it to
the after-tax discounted free cash flow attributed to the trade name. The discount rate used is based on an estimated weighted average cost of capital and the
anticipated risk for intangible assets. The valued trade names have an indefinite life based on our plans and expectations for the trade names going forward and
are reviewed for impairment annually, or more frequently when indicators of impairment exist.

Intellectual property and technology (“IP”) is a design, work or invention that is the result of creativity to which one has ownership rights that may be
protected through a patent, copyright, trademark or service mark. IP is valued using the relief-from-royalty valuation method. The method uses a royalty rate
based on comparable marketplace royalty agreements for similar types of IP and applies it to the after-tax discounted free cash flow attributed to the IP. The
discount rate used is based on an estimated weighted average cost of capital and the anticipated risk for intangible assets. The IP is amortized following the
pattern in which the expected benefits will be consumed or otherwise used up over each component’s useful life, based on our plans and expectations for the IP
going forward, which is generally the underlying IP’s legal expiration dates. IP is reviewed for impairment annually, or more frequently when indicators of
impairment exist.

Customer relationships are intangible assets that consist of historical and factual information about customers and contacts collected from repeat

transactions with customers, with or without any underlying contracts. The information is generally organized as customer lists or customer databases. We have
the expectation of repeat patronage from these customers based on the customers’ historical purchase activity, which creates the intrinsic value over a finite
period of time and translates into the expectation of future revenue, income, and cash flow. Customer relationships are valued using projected operating income,
adjusted for estimated future existing customer growth less estimated future customer attrition, net of charges for net tangible assets, IP charge, trade name
charge and work force. The concluded value is the after-tax discounted free cash flow. Customer relationships are reviewed for impairment annually, or more
frequently when indicators of impairment exist.

See Note I - Goodwill and Intangible Assets.

Leases

We lease railroad cars, office space, mining property, mining/processing equipment, and transportation and other equipment. Operating leases are included

in lease right-of-use (“ROU”) assets, current portion of operating lease liabilities, and operating lease liabilities in our consolidated balance sheets. Finance
leases are included in lease right-of-use assets, current portion of long-term debt, and long-term debt in our consolidated balance sheets. Leases with an initial
term of 12 months or less are not recorded on the balance sheet. ROU assets represent our right to use an underlying asset for the lease term and lease liabilities
represent our obligation to make lease payments arising from the lease. ROU assets and liabilities are recognized at the commencement date of the lease based
on the present value of lease payments over the lease term. As most of our leases do not provide an implicit rate, we use our incremental borrowing rate based
on the information available at the commencement date in determining the present value of lease payments. The ROU assets also include any lease payments
made at or before the commencement date of the lease and excludes lease incentives. Our lease terms may include options to extend or terminate the lease when
it is reasonably certain that we will exercise that option. Lease expense for lease payments is recognized on a straight-line basis over the lease term. We have
lease agreements with lease and non-lease components, the latter of which are generally accounted for separately. See Note R - Leases.

We periodically evaluate whether current events or circumstances indicate that the carrying value of our ROU assets exceeds fair value. If circumstances

indicate an impairment exists, we estimate fair value primarily utilizing internally developed cash flow models and quoted market prices, discounted at an
appropriate weighted average cost of capital. If the undiscounted cash flows are less than the carrying value of the assets, we recognize an impairment loss
equal to the amount by which the carrying value exceeds the fair value of the assets.

Revenue Recognition

Products

We derive our product sales by mining and processing minerals that our customers purchase for various uses. Our product sales are primarily a function

of the price per ton and the number of tons sold. We primarily sell our products through individual purchase orders executed under short-term price agreements
or at prevailing market rates. The amount invoiced reflects product, transportation and additional handling services as applicable, such as storage, transloading
the product from railcars to trucks and last mile logistics to the customer site. We invoice most of our product customers on a per shipment basis, although for
some larger customers, we consolidate invoices weekly or monthly. Standard collection terms are net 30 days, although extended terms are offered in
competitive situations.

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We recognize revenue for products and materials at a point in time following the transfer of control of such items to the customer, which typically occurs
upon shipment or delivery depending on the terms of the underlying contracts. We account for shipping and handling activities related to product and material
sales contracts with customers as costs to fulfill our promise to transfer the associated products pursuant to the accounting policy election allowed under ASC
606-10-25-18b. Accordingly, we record amounts billed for shipping and handling costs as a component of net sales and accrue and classify related costs as a
component of cost of sales at the time revenue is recognized.

For a limited number of customers, we sell under long-term, minimum purchase supply agreements. These agreements define, among other commitments,

the volume of product that our customers must purchase, the volume of product that we must provide and the price that we will charge and that our customers
will pay for each product. Prices under these agreements are generally fixed and subject to certain contractual adjustments. Sometimes these agreements may
undergo negotiations regarding pricing and volume requirements, which may often occur in volatile market conditions. While these negotiations continue, we
may deliver product at prices or at volumes below the requirements in our existing supply agreements. An executed order specifying the type and quantity of
product to be delivered, in combination with the noted agreements, comprise our contracts in these arrangements.

Service

We derive our service revenues primarily through the provision of transportation, equipment rental, and contract labor services to companies in the oil and
gas industry. Transportation services typically consist of transporting customer proppant from storage facilities to proximal well-sites and are contracted through
work orders executed under established pricing agreements. The amount invoiced reflects the transportation services rendered. Equipment rental services
provide customers with use of either dedicated or nonspecific wellhead proppant delivery equipment solutions for contractual periods defined either through
formal lease agreements or executed work orders under established pricing agreements. The amounts invoiced reflect the length of time the equipment set was
utilized in the billing period. Contract labor services provide customers with proppant delivery equipment operators through work orders executed under
established pricing agreements. The amounts invoiced reflect the amount of time our labor services were utilized in the billing period.

We typically invoice our customers on a weekly or monthly basis; however, some customers receive invoices upon well-site operation completion.
Standard collection terms are net 30 days, although extended terms are offered in competitive situations. We typically recognize revenue for specific, dedicated
equipment set rental arrangements under ASC 842, Leases. For the remaining components of service revenue, we have applied the practical expedient allowed
under ASC 606-10-55-18 to recognize transportation revenues in proportion to the amount we have the right to invoice.

Contracts with Multiple Performance Obligations

From time to time, we may enter into contracts that contain multiple performance obligations, such as work orders containing a combination of product,

transportation, equipment rentals, and contract labor services. For these arrangements, we allocate the transaction price to each performance obligation
identified in the contract based on relative standalone selling prices, or estimates of such prices, and recognize the related revenue as control of each individual
product or service is transferred to the customer, in satisfaction of the corresponding performance obligations. We typically invoice our customers on a weekly
or monthly basis; however, some customers received invoices upon well-site operation completion. Standard collection terms are net 30 days, although
extended terms are offered in competitive situations.

Taxes Collected from Customers and Remitted to Governmental Authorities. 

We exclude from our measurement of transaction prices all taxes assessed by governmental authorities that are both (i) imposed on and concurrent with a
specific revenue-producing transaction and (ii) collected from customers. Accordingly, such tax amounts are not included as a component of net sales or cost of
sales.

See Note T - Revenue.

Deferred Revenues

For a limited number of customers, we enter into supply agreements which give customers the right to make advanced payments toward the purchase of

certain products at specified volumes over an average initial period of one to fifteen years. These payments represent consideration that is unconditional and for
which we have yet to transfer the related product. These payments are recorded as contract liabilities referred to as “deferred revenues” upon receipt and
recognized as revenue upon delivery of the related product.

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Unbilled Receivables

Revenues recognized in advance of invoice issuance create assets referred to as “unbilled receivables.” Any portion of our unbilled receivables for which
our right to consideration is conditional on a factor other than the passage of time is considered a contract asset. These assets are presented on a combined basis
with accounts receivable and are converted to accounts receivable once billed.

Debt Issuance Costs

We defer costs directly associated with acquiring third-party financing, primarily loan origination costs and related professional expenses. Debt issuance
costs are deferred and amortized using the effective interest rate method over the term of our senior secured Term Loan facility and the straight-line method for
our Revolver facility. Debt issuance costs related to long-term debt are reflected as a direct deduction from the carrying amount of the debt. Amortization
included in interest expense was $4.8 million for the year ended December 31, 2022, and $5.1 million and $5.1 million for the years ended December 31, 2021
and 2020. See Note K - Debt.

Employee Benefit Plans

We provide a range of benefits to our employees and retired employees, including pensions and post-retirement healthcare and life insurance benefits. We

record annual amounts relating to these plans based on calculations specified by generally accepted accounting principles, which include various actuarial
assumptions, including discount rates, assumed rates of returns, compensation increases, turnover rates, mortality tables, and healthcare cost trend rates. We
review the actuarial assumptions on an annual basis and make modifications to the assumptions based on current rates and trends when it is deemed appropriate
to do so. As required by U.S. generally accepted accounting principles, the effect of the modifications is generally recorded or amortized over future periods.
We believe that the assumptions utilized in recording our obligations under the plans are reasonable based on advice from our actuaries and information as to
assumptions used by other employers. See Note Q - Pension and Post-Retirement Benefits.

Environmental Costs

Environmental costs, other than qualifying capital expenditures, are accrued at the time the exposure becomes known and costs can be reasonably
estimated. Costs are accrued based upon management’s estimates of all direct costs, after taking into account expected reimbursement by third parties (primarily
the sellers of acquired businesses) and are reviewed by outside consultants. Environmental costs are charged to expense unless a settlement with an
indemnifying party has been reached.

Self-Insurance

We are self-insured for various levels of employee health insurance coverage, workers’ compensation and third-party product liability claims alleging

occupational disease. We purchase insurance coverage for claim amounts which exceed our self-insured retentions. Depending on the type of insurance, these
self-insured retentions range from $0.1 million to $0.5 million per occurrence. Our insurance reserves are accrued based on estimates of the ultimate cost of
claims expected to occur during the covered period. These estimates are prepared with the assistance of outside actuaries and consultants. Our actuaries
periodically review the volume and amount of claims activity, and based upon their findings, we adjust our insurance reserves accordingly. The ultimate cost of
claims for a covered period may differ from our original estimates. The current portion of our self-insurance reserves is included in accrued liabilities and the
non-current portion is included in other long-term obligations in our Balance Sheets. As of December 31, 2022 and 2021, our self-insurance reserves totaled
$5.6 million and $5.8 million, respectively, of which $1.8 million and $2.1 million, respectively, were classified as current.

Research and Development Costs

We may incur immaterial internal research and development (“R&D”) expenditures, and research and development conducted for others, all of which are

expensed as incurred, and included in selling, general and administrative expense. R&D costs may include, but are not limited to, research and administrative
salaries, contractor fees, building costs, utilities, administrative expenses, and allocations of corporate costs.

Advertising Costs

We recognize advertising expense when incurred as selling, general and administrative expense. Advertising costs have not been a significant component

of expense for the years ended December 31, 2022, 2021, or 2020.

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Equity-based Compensation

We grant stock options, restricted stock, restricted stock units and performance share units to certain of our employees and directors under the Amended

and Restated U.S. Silica Holdings, Inc. 2011 Incentive Compensation Plan. We recognize the cost of employee services rendered in exchange for awards of
equity instruments.

Vesting of restricted stock and restricted stock units is based on the individual continuing to render service over a pre-defined vesting schedule, generally

three years. Cash dividend equivalents are accrued and paid to the holders of time-based restricted stock units and restricted stock. The fair value of the
restricted stock awards is equal to the market price of our stock at date of grant. The restricted award-related compensation expense is recognized on a straight-
line basis over the vesting period.

We grant performance share units to certain employees in which the number of shares of common stock ultimately received is determined based on
achievement of certain performance thresholds over a specified performance period (generally three years) in accordance with the stock award agreement. Cash
dividend equivalents are not accrued or paid on performance share units. We recognize expense based on the estimated vesting of our performance share units
granted and the grant date market price. The estimated vesting of the performance share units is principally based on the probability of achieving certain
financial performance levels during the vesting periods. In the period it becomes probable that the minimum performance criteria specified in the award
agreement will be achieved, we recognize expense for the proportionate share of the total fair value of the award related to the vesting period that has already
lapsed. The remaining fair value of the award is expensed on a straight-line basis over the remaining vesting period.

We grant certain employees performance share units, the vesting of which is based on our total shareholder return (“TSR”) ranking among a peer group

over a three-year period. The number of units that will vest will depend on the percentage ranking of our TSR compared to the TSRs for each of the companies
in the peer group over the performance period. For these awards subject to market conditions, a binomial-lattice model (i.e., Monte Carlo simulation model) is
used to fair value these awards at grant date. We also grant certain employees performance share units, the vesting of which is based on adjusted free cash flow
("ACF") targets. The number of ACF measured units that will vest will be based on ACF achievement versus target. The ACF targets are set annually and are
approved by the Board of Directors. The related compensation expense is recognized on a straight-line basis over the vesting period.

See Note O - Equity-based Compensation.

Income Taxes

Deferred taxes are recognized on the liability method whereby deferred tax assets are recognized for deductible temporary differences and operating loss

and tax credit carry forwards and deferred tax liabilities are recognized for taxable temporary differences. This approach requires recognition of deferred tax
liabilities and assets for the expected future tax consequences of events that have been included in the financial statements or tax returns. Under this method,
deferred tax liabilities and assets are determined based upon the difference between the financial statement and tax basis of assets and liabilities using enacted
tax rates in effect for the year in which the expenses are expected to reverse. Valuation allowances are provided if, based on the weight of available evidence, it
is more likely than not that some or all of the deferred tax assets will not be realized.

We recognize a tax benefit associated with an uncertain tax position when, in management’s judgment, it is more likely than not that the position will be

sustained upon examination by a taxing authority. For a tax position that meets the more likely than not recognition threshold, we initially and subsequently
measure the tax benefit as the largest amount that we judge to have a greater than 50% likelihood of being realized upon ultimate settlement with a taxing
authority. The liability associated with unrecognized tax benefits is adjusted periodically due to changing circumstances, such as the progress of tax audits, case
law developments and new or emerging legislation. Such adjustments are recognized entirely in the period in which they are identified. The effective tax rate
includes the net impact of changes in the liability for unrecognized tax benefits and subsequent adjustments as considered appropriate by management.

See Note S - Income Taxes.

Foreign Currency Translation

For our operations in countries where the functional currency is other than the U.S. dollar, balance sheet amounts are translated using the exchange rate in

effect at the balance sheet date. Income statement amounts are translated monthly using the average exchange rate for the respective month. The gains and
losses resulting from the changes in exchange rates from year-to-year are recorded as a component of accumulated other comprehensive income or loss as
currency translation

93

adjustments, net of tax. Any gains or losses on transactions in currencies other than the functional currency are included in other income (expense), net,
including interest income.

Comprehensive Income (loss)

In addition to net income (loss), comprehensive income (loss) includes all changes in equity during a period, such as adjustments to minimum pension

liabilities and the effective portion of changes in fair value of derivative instruments that qualify as cash flow hedges.

Business Combinations

We account for business combinations using the acquisition method of accounting. Under this method, acquired assets, including separately identifiable

intangible assets and any assumed liabilities, are recorded at their acquisition date estimated fair value. The excess of purchase price over the fair value amounts
assigned to the assets acquired and liabilities assumed represents the goodwill amount resulting from the acquisition. Determining the fair value of assets
acquired and liabilities assumed involves the use of significant estimates and assumptions. See Note E - Business Combinations.    

New Accounting Pronouncements Recently Adopted

None.

New Accounting Pronouncements Not Yet Adopted

In March 2020, the FASB issued ASU 2020-04, Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial

Reporting followed by ASU 2021-01, Reference Rate Reform (Topic 848): Scope, issued in January 2021, to provide clarifying guidance regarding the scope of
Topic 848. ASU 2020-04 was issued to provide optional guidance for a limited period of time to ease the potential burden in accounting for (or recognizing the
effects of) reference rate reform on financial reporting. Generally, the guidance is to be applied as of any date from the beginning of an interim period that
includes or is subsequent to March 12, 2020, or prospectively from a date within an interim period that includes or is subsequent to March 12, 2020, up to the
date that the financial statements are available to be issued. ASU 2020-04 and ASU 2021-01 are effective for all entities through December 31, 2022. In April
2022, the FASB proposed to extend the effective date through December 31, 2024 and affirmed this decision in December 2022. As of December 31, 2022, we
have not elected to use the optional guidance and continue to evaluate the options provided by ASU 2020-04 and ASU 2021-01. See Note K - Debt for
discussion of the use of the adjusted LIBOR rate in connection with borrowings under our senior secured revolving credit facility.

NOTE C—EARNINGS PER SHARE

Basic earnings per common share is computed by dividing income available to common stockholders by the weighted average number of common shares

outstanding for the period. Diluted earnings per common share is computed similarly to basic earnings per common share except that the weighted average
number of common shares outstanding is increased to include the number of additional common shares that would have been outstanding if the potentially
dilutive common shares had been issued.

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The following table shows the computation of basic and diluted earnings per share:

In thousands, except per share amounts

Numerator:

Year ended December 31,
2021

2020

2022

Net income (loss) attributable to U.S. Silica Holdings, Inc.

$

78,176  $

(33,761) $

(114,094)

Denominator:

Weighted average shares outstanding
Diluted effect of stock awards

Weighted average shares outstanding assuming dilution

Earnings (loss) per share attributable to U.S. Silica Holdings, Inc.:

Basic earnings (loss) per share

Diluted earnings (loss) per share

75,512 
2,158 
77,670 

74,350 
— 
74,350 

73,634 
— 
73,634 

$

$

1.04  $

1.01  $

(0.45) $

(0.45) $

(1.55)

(1.55)

Potentially dilutive shares are excluded from the calculation of diluted weighted average shares outstanding and diluted earnings per share if we are in a

loss position. Certain stock options, restricted stock awards and performance share units were excluded from the computation of diluted earnings per share
because their effect would have been anti-dilutive. Such potentially dilutive shares and stock awards (in thousands) excluded from the calculation of diluted
earnings (loss) per common share were as follows:

Potentially dilutive shares excluded
Stock options excluded
Restricted stock and performance share units awards excluded

Year ended December 31,
2021

2020

2022

— 
509 
36 

1,714 
667 
66 

238 
826 
3,435 

NOTE D—ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS)

Accumulated Other Comprehensive Income (Loss)

Accumulated other comprehensive income (loss) consists of fair value adjustments associated with cash flow hedges, accumulated adjustments for net

experience gains or losses and prior service cost related to employee benefit plans and foreign currency translation adjustments, net of tax. The following table
presents the changes in accumulated other comprehensive income (loss) by component (in thousands): 

Unrealized loss on cash
flow hedges

Foreign currency
translation adjustments

Pension and other post-
retirement benefits
liability

Total

For the Year Ended December 31, 2022

Beginning Balance

Other comprehensive (loss) income before reclassifications
Amounts reclassed from accumulated other comprehensive
loss

Ending Balance

$

$

—  $

(2,342)

— 
(2,342) $

(417) $
(845)

— 
(1,262) $

766  $

1,172 

(57)
1,881  $

349 
(2,015)

(57)
(1,723)

Any amounts reclassified from accumulated other comprehensive income (loss) related to pension and other post-retirement benefits are included in the

computation of net periodic benefit costs at their pre-tax amounts.

95

 
 
 
 
 
NOTE E—BUSINESS COMBINATIONS

During the first quarter of 2020, we settled multiple intellectual property and contractual lawsuits involving our SandBox Logistics unit and Arrows Up,

LLC. As part of the settlement, SandBox Logistics took control of Arrows Up's existing business, including all equipment and sand logistics contracts, while
also receiving a cash payment.

We accounted for the acquisition of Arrows Up, LLC under the acquisition method of accounting in accordance with ASC 805, Business Combinations.

Estimates of fair value included in the Consolidated Financial Statements represented our best estimates and valuations. In accordance with the acquisition
method of accounting, the fair values were subject to adjustment until we completed our analysis, which was during the first quarter of 2021. This business
combination resulted in a bargain purchase pursuant to ASC 805-30-25 because no consideration was paid for the fair value of assets acquired and liabilities
assumed. The fair value of assets acquired, which included cash, accounts receivable, inventories, lease right-of-use assets, and property plant, and equipment,
was $20.1 million. The fair value of liabilities assumed, which included lease liabilities and other long-term liabilities, was $2.5 million. A gain on bargain
purchase of $17.6 million was recorded in "Other income, net, including interest income" in the Consolidated Statement of Operations.

During the first quarter of 2021, we recorded a $0.1 million increase to accounts receivable, which was our final adjustment to the purchase price. The

total adjustments during the measurement period of $2.4 million were recorded as a net decrease to the initial gain on bargain purchase and recorded in "Other
(expense) income, net, including interest income" in the Consolidated Statement of Operations.

96

NOTE F—ACCOUNTS RECEIVABLE

Accounts receivable (in thousands) consisted of the following:

Trade receivables
Less: Allowance for credit losses

Net trade receivables

Other receivables

(1)

Total accounts receivable

December 31, 2022

December 31, 2021

$

$

209,683  $
(5,691)
203,992 
4,639 
208,631  $

182,992 
(5,248)
177,744 
25,015 
202,759 

At December 31, 2022 and 2021, other receivables included zero and $21.5 million of refunds related to NOL carryback claims filed for various tax years in

(1)
accordance with certain provisions of the CARES Act.

We classify our trade receivables into the following portfolio segments: Oil & Gas Proppants and Industrial & Specialty Products, which also aligns with
our reporting segments. We estimate the allowance for credit losses based on historical collection trends, the age of outstanding receivables, risks attributable to
specific customers, such as credit history, bankruptcy or other going concern issues, and current economic and industry conditions. If events or circumstances
indicate that specific receivable balances may be impaired, further consideration is given to the collectability of those balances and the allowance is adjusted
accordingly. Past due balances are written off when we have exhausted our internal and external collection efforts and have been unsuccessful in collecting the
amount due.

The following table reflects the change of the allowance for credit losses (in thousands) disaggregated by portfolio segments:

Beginning balance, December 31, 2021

Allowance for credit losses
Write-offs

Ending balance, December 31, 2022

Oil & Gas Proppants
$

4,625  $
(469)
(128)
4,028  $

$

Industrial & Specialty
Products

Total

623  $

1,086 
(46)
1,663  $

5,248 
617 
(174)
5,691 

Our ten largest customers accounted for approximately 40%, 40% and 34% of total sales during the years ended December 31, 2022, 2021 and 2020,

respectively. No single customer accounted for more than 10% of our total sales during the years ended December 31, 2022, 2021 and 2020. At December 31,
2022 and 2021, none of our customers' accounts receivable represented 10% or more of our total trade accounts receivable.

NOTE G—INVENTORIES

Inventories (in thousands) consisted of the following:

Supplies
Raw materials and work in process
Finished goods

Total inventories

December 31, 2022

December 31, 2021

$

$

54,805  $
47,042 
45,779 
147,626  $

45,605 
36,529 
33,579 
115,713 

97

NOTE H—PROPERTY, PLANT AND MINE DEVELOPMENT

Property, plant and mine development (in thousands) consisted of the following:

Mining property and mine development
Asset retirement cost
Land
Land improvements
Buildings
Machinery and equipment
Furniture and fixtures
Construction-in-progress

Accumulated depletion, depreciation, amortization and impairment charges

Total property, plant and mine development, net

December 31, 2022

December 31, 2021

$

$

789,601  $
8,869 
53,128 
76,456 
73,151 
1,217,933 
3,922 
55,696 
2,278,756 
(1,099,922)
1,178,834  $

789,122 
22,283 
55,541 
76,248 
72,207 
1,189,548 
3,932 
35,060 
2,243,941 
(985,295)
1,258,646 

Depreciation, depletion, and amortization expense related to property, plant and mine development for the years ended December 31, 2022 and 2021 was

$128.4 million and $149.6 million, respectively.

NOTE I—GOODWILL AND INTANGIBLE ASSETS

The changes in the carrying amount of goodwill (in thousands) by business segment consisted of the following:

Balance at December 31, 2020

Impairment losses
Balance at December 31, 2021

Impairment losses
Balance at December 31, 2022

Oil & Gas Proppants
Segment

Industrial & Specialty
Products Segment

Total

—  $

185,649  $

— 
— 

— 
—  $

— 
185,649 

— 
185,649  $

$

$

185,649 

— 
185,649 

— 
185,649 

Goodwill and trade names are evaluated for impairment annually as of October 31, or more frequently when indicators of impairment exist. We evaluated
events and circumstances since the date of our last qualitative assessment, including macroeconomic conditions, industry and market conditions, and our overall
financial performance. There were no triggering events identified, therefore, no impairment charges were recorded related to goodwill or trade names for the
years ended December 31, 2022 and 2021.

98

 
The changes in the carrying amount of intangible assets (in thousands) consisted of the following:

December 31, 2022

December 31, 2021

Gross
Carrying
Amount

Accumulated
Amortization

Impairments

Net

Gross
Carrying
Amount

Accumulated
Amortization

Impairments

Net

Technology and intellectual
property
Customer relationships
 Total definite-lived
intangible assets:

Trade names
Other

Total intangible assets:

$

$

$

71,651  $
66,999 

138,650  $
64,240 
700 
203,590  $

(29,990) $
(32,791)

(62,781) $

— 
— 

(62,781) $

—  $
— 

—  $
— 
— 
—  $

41,661  $
34,208 

71,209  $
66,999 

75,869  $
64,240 
700 
140,809  $

138,208  $
64,240 
700 
203,148  $

(25,069) $
(27,987)

(53,056) $

— 
— 

(53,056) $

(38) $
— 

(38) $
— 
— 
(38) $

46,102 
39,012 

85,114 
64,240 
700 
150,054 

Estimated useful life of technology and intellectual property is 15 years. Estimated useful life of customer relationships is a range of 13 - 20 years.

Amortization expense was $9.7 million, $9.7 million and $10.3 million for the years ended December 31, 2022, 2021, and 2020, respectively.

At December 31, 2022, the estimated amortization expense related to definite-lived intangible assets (in thousands) for the five succeeding years is as

follows:

2023
2024
2025
2026
2027

$
$
$
$
$

9,696 
9,698 
9,696 
9,696 
9,696 

NOTE J—ACCOUNTS PAYABLE AND ACCRUED LIABILITIES

Accounts payable and accrued liabilities (in thousands) consisted of the following:

Trade payables
Accrued salaries and wages
Accrued vacation liability
Current portion of liability for pension and post-retirement benefits
Accrued healthcare liability
Accrued property taxes and sales taxes
Current portion of derivative liability
Other accrued liabilities

Accounts payable and accrued liabilities

December 31,

2022

2021

$

$

182,555  $
10,911 
3,093 
1,118 
1,492 
4,287 
2,312 
10,471 
216,239  $

134,494 
11,347 
2,847 
1,227 
1,619 
4,625 
— 
11,511 
167,670 

Other accrued liabilities consist of employer related expenses, royalties payable, accrued interest payable, and other items.

99

 
 
 
 
NOTE K—DEBT

Debt (in thousands) consisted of the following:

Senior secured credit facility:

Revolver expiring May 1, 2023 (8.44% at December 31, 2022 and 4.13% at December 31, 2021)
Term Loan facility—final maturity May 1, 2025 (8.44% at December 31, 2022 and 5.00%
December 31, 2021)

Less: Unamortized original issue discount
Less: Unamortized debt issuance cost

Insurance financing notes payable
Finance leases

Total debt

Less: current portion

Total long-term portion of debt

Senior Secured Credit Facility

December 31, 2022

December 31, 2021

—  $

— 

1,059,062 
(2,035)
(8,922)
5,628 
3,260 
1,056,993 
(19,535)
1,037,458  $

1,222,000 
(3,350)
(15,200)
4,424 
3,546 
1,211,420 
(18,285)
1,193,135 

$

$

On May 1, 2018, we entered into a Third Amended and Restated Credit Agreement (the "Credit Agreement"), which increased our existing senior debt by
entering into a new $1.380 billion senior secured Credit Facility, consisting of a $1.280 billion term loan (the "Term Loan") and a $100 million revolving credit
facility (the "Revolver") (collectively the "Credit Facility") that may also be used for swingline loans or letters of credit, and we may elect to increase the term
loan in accordance with the terms of the Credit Agreement. Borrowings under the Credit Agreement will bear interest at variable rates as determined at our
election, at LIBOR or a base rate, in each case, plus an applicable margin. In addition, under the Credit Agreement, we are required to pay a per annum facility
fee and fees for letters of credit. The Credit Agreement is secured by substantially all of our assets and of our domestic subsidiaries' assets and a pledge of the
equity interests in such entities. The Term Loan matures on May 1, 2025, and the Revolver expires on May 1, 2023. We capitalized $38.7 million in debt
issuance costs and original issue discount as a result of the new Credit Agreement.

The Credit Agreement contains covenants that, among other things, limit our ability, and certain of our subsidiaries' abilities, to create, incur or assume

indebtedness and liens, to make acquisitions or investments, to sell assets and to pay dividends. The Credit Agreement also requires us to maintain a
consolidated leverage ratio of no more than 3.75:1.00 as of the last day of any fiscal quarter whenever usage of the Revolver (other than certain undrawn letters
of credit) exceeds 30% of the Revolver commitment. These covenants are subject to a number of important exceptions and qualifications. The Credit
Agreement includes events of default and other affirmative and negative covenants that are usual for facilities and transactions of this type. As of December 31,
2022 and 2021, we were in compliance with all covenants in accordance with our senior secured Credit Facility.

Term Loan

At December 31, 2022, contractual maturities of our senior secured Credit Facility (in thousands) are as follows:

2023
2024
2025
2026
2027
Thereafter

Total

$

$

12,800 
12,800 
1,033,462 
— 
— 
— 
1,059,062 

100

Revolving Line-of-Credit

We have a $100.0 million Revolver with zero drawn and $21.5 million allocated for letters of credit as of December 31, 2022, leaving $78.5 million

available under the Revolver.

Based on our consolidated leverage ratio of 2.99:1.00 as of December 31, 2022, we have access to the full availability of the Revolver. If our consolidated

leverage ratio exceeds 3.75:1.00, we may draw up to $30.0 million without the consent of our lenders.

Debt Repurchases

During the three months ended September 30, 2022, we repurchased outstanding debt under the Term Loan in the amount of $100 million discounted at a
rate of 97%. A proportionate share of debt issuance and original discount costs were written off in conjunction with this repurchase which resulted in additional
expense of approximately $1.2 million. As a result, we recorded a gain on extinguishment of debt in the amount of $1.7 million. The gain on extinguishment
was recorded in Other income, net, including interest income in the Consolidated Statements of Operations.

During the three months ended December 31, 2022, we repurchased outstanding debt under the Term Loan in the amount of $50 million discounted at a

rate of 96.25%. A proportionate share of debt issuance and original discount costs were written off in conjunction with this repurchase which resulted in
additional expense of approximately $0.6 million. As a result, we recorded a gain on extinguishment of debt in the amount of $1.2 million. The gain on
extinguishment was recorded in Other income, net, including interest income in the Consolidated Statements of Operations.

Note Payable Secured by Royalty Interest

In conjunction with the acquisition of New Birmingham, Inc. in August 2016, we assumed a note payable secured by a royalty interest. During the fourth

quarter of 2020, we executed an amendment to the note payable which settled the outstanding balance in its entirety in exchange for a one-time payment of
$2.55 million. Future royalties may be owed under this amended agreement if we resume production at our Tyler facility, however, we have no plans to resume
production. Therefore, no amounts have been accrued. The settlement of the note payable resulted in a gain of $8.3 million which was recorded in Other
income, net, including interest income in the Consolidated Statements of Operations.

Insurance Financing Notes Payable

During the third quarter of 2022, we renewed our insurance policies and financed the payments through notes payable with a stated interest rate of 6.0%.
These payments will be made in installments throughout a nine-month period and, as such, were classified as current debt. As of December 31, 2022, the notes
payable had a balance of $5.6 million.

NOTE L—ASSET RETIREMENT OBLIGATIONS

Mine reclamation or future remediation costs for inactive mines are accrued based on management’s best estimate at the end of each period of the costs

expected to be incurred at a site. Such cost estimates include, where applicable, ongoing care, maintenance and monitoring costs. Changes in estimates at
inactive mines are reflected in earnings in the period an estimate is revised. Liabilities related to our asset retirement obligations are recorded in other long-term
liabilities on our balance sheets. Changes in the asset retirement obligations (in thousands) are as follows:

Beginning balance
Accretion
Additions and revisions of estimates
Payments

Ending balance

December 31, 2022

December 31, 2021

$

$

32,049  $
1,498 
(12,753)
(62)
20,732  $

24,717 
1,450 
5,882 
— 
32,049 

The decrease in liability is primarily attributable to revisions of estimates of reclamation costs, mainly related to change in interest rates.

101

NOTE M—FAIR VALUE ACCOUNTING

Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most
advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Fair value is estimated by
applying the following hierarchy, which prioritizes the inputs used to measure fair value into three levels and bases the categorization within the hierarchy upon
the lowest level of input that is available and significant to the fair value measurement:

    Level 1—Quoted prices in active markets for identical assets or liabilities.

    Level 2—Observable inputs other than quoted prices in active markets for identical assets and liabilities, quoted prices for identical or similar assets or
liabilities in inactive markets, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or
liabilities.

    Level 3—Inputs that are generally unobservable and typically reflect management’s estimate of assumptions that market participants would use in

pricing the asset or liability.

Cash Equivalents

Due to the short-term maturity, we believe our cash equivalent instruments at December 31, 2022 and 2021, approximate their reported carrying values,

therefore we have classified our cash equivalents as Level 1 of the fair value hierarchy.

Long-Term Debt, Including Current Maturities

We believe that the fair values of our long-term debt, including current maturities, approximate their carrying values based on their effective interest rates

compared to current market rates, therefore we have classified our long-term debt as Level 1 of the fair value hierarchy.

Derivative Instruments

The estimated fair value of our derivative instruments is recorded at each reporting period and is determined based on inputs that are readily available in
public markets or can be derived from information available in publicly quoted markets. Therefore, we have classified these swap agreements as Level 2 of the
fair value hierarchy.

102

NOTE N—DERIVATIVE INSTRUMENTS

Cash Flow Hedges of Natural Gas Price Risk

Natural gas is the primary fuel source used for drying in the commercial silica production process. In the past, the price of natural gas has been volatile,

and we believe this volatility may continue. In order to manage our exposure to natural gas price increases, we have entered into natural gas swaps. All of these
swap agreements commenced in December 2022. The derivative instruments are recorded on the balance sheet within other current or long-term assets or
liabilities based on maturity dates at their fair values. As of December 31, 2022, the fair value of our natural gas swaps was a liability of $3.1 million, of which
$2.3 million is classified within accounts payable and accrued liabilities on our balance sheet and $0.8 million is classified within other long-term obligations
on our balance sheet.

We have designated the natural gas swap agreements as qualified cash flow hedges. Accordingly, the effective portion of the gain or loss on the derivative

instrument is reported as a component of other comprehensive income and recognized in earnings in the same period or periods during which the hedged
transaction affects earnings.

The following table summarizes the fair value of our derivative instruments (in thousands, except contract/notional amount). See Note M - Fair Value

Accounting for more information regarding the estimated fair values of our derivative instruments.

December 31, 2022

December 31, 2021

Maturity
Date

Contract/Notional
Amount (MMBtu)

Carrying
Amount

Fair
 Value

Maturity
Date

Contract/Notional
Amount

Carrying
Amount

Fair
 Value

Natural Gas - W. Texas (WAHA)
- Inside FERC
Natural Gas - W. Texas (WAHA)
- Inside FERC
Natural Gas - Henry Hub -
NYMEX
Natural Gas - Henry Hub -
NYMEX
Natural Gas - Henry Hub -
NYMEX

2023

2024

2023

2024

2025

1,200,000  $

(1,887) $

(1,887)

870,000  $

(656) $

(656)

300,000  $

(425) $

(425)

120,000  $

(85) $

90,000  $

(35) $

(85)

(35)

N/A

N/A

N/A

N/A

N/A

—  $

—  $

—  $

—  $

—  $

—  $

—  $

—  $

—  $

—  $

— 

— 

— 

— 

— 

During the year ended December 31, 2022, we had no ineffectiveness for the natural gas swap derivatives.

The following table summarizes the effect of derivative instruments (in thousands) on our income statements and our consolidated statements of

comprehensive income:

Deferred losses from derivatives in OCI, beginning of period

(Loss) gain recognized in OCI from derivative instruments

Deferred losses from derivatives in OCI, end of period

NOTE O—EQUITY-BASED COMPENSATION

2022

Year ended December 31,
2021

2020

$

$

—  $

(2,342)
(2,342) $

—  $
— 
—  $

(3,053)
3,053 
— 

In July 2011, we adopted the U.S. Silica Holdings, Inc. 2011 Incentive Compensation Plan (the “2011 Plan”), which was amended and restated in May
2015, amended and restated effective February 1, 2020, amended and restated effective May 13, 2021 and amended and restated effective May 12, 2022. The
2011 Plan provides for grants of stock options, restricted stock, performance share units and other incentive-based awards. We believe our 2011 Plan aligns the
interests of our employees and directors with those of our common stockholders. At December 31, 2022, we had 2,649,220 shares of common stock that may be
issued under the 2011 Plan. We use a combination of treasury stock and new shares if necessary to satisfy option exercises or vesting of restricted awards and
performance share units.

103

 
 
 
 
 
 
 
Stock Options

The following table summarizes the status of, and changes in, our stock option awards:

Outstanding at December 31, 2021

Granted
Exercised
Forfeited
Expired

Outstanding at December 31, 2022
Exercisable at December 31, 2022

Number of
Shares

Weighted
Average
Exercise Price

Aggregate Intrinsic
Value

666,718  $
—  $
(90,000) $
—  $
(68,195) $
508,523  $
508,523  $

30.84  $
—  $
10.61  $
—  $
17.46  $
36.22  $

36.22  $

— 
— 
613 
— 
— 
— 

— 

Weighted
Average
Remaining
Contractual Term in
Years
2.4 years

2.0 years

2.0 years

There were no grants of stock options during the years ended December 31, 2022, 2021 and 2020.

The following table summarizes stock option exercise activity:

Options exercised (in actual shares)
Intrinsic value of options exercised (in thousands)
Cash received from options exercised (in thousands)
Tax benefit realized from options exercised (in thousands)

2022

As of December 31,
2021

2020

$
$
$

90,000 

613  $
955  $
148  $

10,164 

44  $
105  $
11  $

— 
— 
— 
— 

As of December 31, 2022, 2021 and 2020, there was no unrecognized compensation expense related to these options. We account for forfeitures as they

occur.

Restricted Stock and Restricted Stock Unit Awards

The following table summarizes the status of, and changes in, our unvested restricted stock awards:

Unvested, December 31, 2021

Granted
Vested
Forfeited

Unvested, December 31, 2022

Number of Shares

Grant Date Weighted
Average Fair Value

1,144,310  $
728,357  $
(401,555) $
(32,726) $
1,438,386  $

8.37 
10.74 
8.97 
9.82 

9.37 

We granted 728,357, 881,261 and 1,590,170 restricted stock and restricted stock unit awards during the years ended December 31, 2022, 2021 and 2020,

respectively. The fair value of the awards was based on the market price of our stock at date of grant.

We recognized $6.8 million, $7.3 million and $8.1 million of equity-based compensation expense related to restricted stock awards during the years

ended December 31, 2022, 2021 and 2020, respectively. As of December 31, 2022, there was $8.2 million of unrecognized compensation expense related to
these restricted stock awards, which is expected to be recognized over a weighted-average period of 1.8 years.

We also granted cash awards during the year ended December 31, 2020. These awards will vest over a period of three years and will be settled in cash. As

such, these awards have been classified as liability instruments. We recognized $0.9 million, $0.9 million and $0.6 million of expense related to these awards
for the years ended December 31, 2022, 2021 and 2020. The liability for these awards is included in accounts payable and other accrued liabilities on our
balance sheets. These awards will be remeasured at fair value each reporting period with resulting changes reflected in our income statements. Estimated
unrecognized expense related to these awards is $0.1 million over a period of 0.1 years.

104

 
 
 
 
 
 
Performance Share Unit Awards

The following table summarizes the status of, and changes in, our performance share unit awards:

Unvested, December 31, 2021

Granted
Vested
Forfeited/Cancelled
Unvested, December 31, 2022

Number of Shares

Grant Date Weighted
Average Fair Value

1,914,589  $
920,681  $
(497,401) $
(45,118) $
2,292,751  $

9.77 
11.79 
14.56 
11.30 

9.51 

We granted 920,681, 886,091 and 1,020,161 of performance share unit awards during the years ended December 31, 2022, 2021 and 2020, respectively.
A portion of these awards was measured against total shareholder return ("TSR"), and a portion was measured against adjusted free cash flow ("ACF") targets.
The grant date weighted average fair value of these awards was estimated to be $11.79, $12.04 and $6.57 for the years ended December 31, 2022, 2021 and
2020, respectively. The number of TSR measured units that will vest will depend on the percentage ranking of our TSR compared to the TSR for each of the
companies in the peer group over the three year period from January 1, 2022 through December 31, 2024 for the 2022 grant, January 1, 2021 through December
31, 2023 for the 2021 grant, and January 1, 2020 through December 31, 2022 for the 2020 grant. The number of ACF measured units that will vest will be
based on ACF achievement versus target. The ACF targets are set annually and are approved by the Board of Directors. The related compensation expense is
recognized on a straight-line basis over the vesting period.

The grant date fair value for the TSR awards was estimated using a Monte Carlo simulation model. The Monte Carlo simulation model requires the use of

highly subjective assumptions. Our key assumptions in the model included the price and the expected volatility of our common stock and our self-determined
peer group companies’ stock, risk-free rate of interest, dividend yields and cross-correlations between our common stock and our self-determined peer group
companies' stock.

We recognized $11.5 million, $11.5 million and $6.8 million of compensation expense related to performance share unit awards during the years ended

December 31, 2022, 2021 and 2020, respectively. As of December 31, 2022, there was $8.7 million of unrecognized compensation expense related to these
performance share unit awards, which is expected to be recognized over a weighted-average period of 1.7 years.

We also granted cash awards during the year ended December 31, 2020. These awards will vest over a period of three years and will be settled in cash. As

such, these awards have been classified as liability instruments. We recognized $1.1 million, $0.7 million and $0.9 million of expense related to these awards
for the years ended December 31, 2022, 2021 and 2020, respectively. The liability for these awards is included in accounts payable and other accrued liabilities
on our balance sheets. These awards will be remeasured at fair value each reporting period with resulting changes reflected in our income statements. Estimated
unrecognized expense related to these awards is $0.1 million over a period of 0.1 years.

105

NOTE P—COMMITMENTS AND CONTINGENCIES

Future Minimum Annual Commitments (in thousands):

Year ending December 31,
2023
2024
2025
2026
2027
Thereafter

Total future purchase commitments

Minimum Purchase Commitments

Minimum Purchase
Commitments

10,606 
4,295 
2,886 
2,180 
1,880 
7,484 
29,331 

$

$

We enter into service agreements with our transload and transportation service providers. Some of these agreements require us to purchase a minimum

amount of services over a specific period of time. Any inability to meet these minimum contract requirements requires us to pay a shortfall fee, which is based
on the difference between the minimum amount contracted for and the actual amount purchased.

Contingent Liability on Royalty Agreement

On May 17, 2017, we purchased reserves in Crane County, Texas, for $94.4 million cash plus contingent consideration. The contingent consideration is a
royalty that is based on the tonnage shipped to third-parties. Because the contingent consideration is dependent on future tonnage sold, the amounts of which are
uncertain, it is not currently possible to estimate the fair value of these future payments. The contingent consideration will be capitalized at the time a payment
is probable and reasonably estimable, and the related depletion expense will be adjusted prospectively.

Other Commitments and Contingencies

Our operating subsidiary, U.S. Silica Company (“U.S. Silica”), has been named as a defendant in various product liability claims alleging silica exposure

causing silicosis. During the years ended December 31, 2022, 2021 and 2020, zero, two and one claims, respectively, were brought against U.S. Silica. As of
December 31, 2022, there were 42 active silica-related products liability claims pending in which U.S. Silica is a defendant. Although the outcomes of these
claims cannot be predicted with certainty, in the opinion of management, it is not reasonably possible that the ultimate resolution of these matters will have a
material adverse effect on our financial position or results of operations that exceeds the accrual amounts.

We have recorded estimated liabilities for these claims in other long-term obligations as well as estimated recoveries under the indemnity agreement and
an estimate of future recoveries under insurance in other assets on our consolidated balance sheets. As of both December 31, 2022 and 2021, other non-current
assets included zero for insurance for third-party products liability claims, and other long-term obligations included $0.8 million and $0.9 million, respectively,
for third-party products liability claims.

Obligations Under Guarantees

    We have indemnified our insurers against any loss they may incur in the event that holders of surety bonds, issued on our behalf, execute the bonds. As of
December 31, 2022, there were $42.6 million in bonds outstanding. The majority of these bonds, $38.6 million, relate to reclamation requirements issued by
various government authorities. Reclamation bonds remain outstanding until the mining area is reclaimed and the authority issues a formal release. The
remaining bonds relate to licenses, permits, and tax collections.

106

NOTE Q— PENSION AND POST-RETIREMENT BENEFITS

We maintain a single-employer noncontributory defined benefit pension plan covering certain employees. The plan is frozen to all new employees. The

plan provides benefits based on each covered employee’s years of qualifying service. Our funding policy is to contribute amounts within the range of the
minimum required and maximum deductible contributions for the plan consistent with a goal of appropriate minimization of the unfunded projected benefit
obligations. The pension plan uses a benefit level per year of service for covered hourly employees and a final average pay method for covered salaried
employees. The plan uses the projected unit credit cost method to determine the actuarial valuation.

We employ a total rate of return investment approach whereby a mix of equities and fixed income investments are used to maximize the long-term return

of plan assets for a prudent level of risk. Risk tolerance is established through careful consideration of plan liabilities, plan funded status, and corporate
financial condition. The investment portfolio contains a diversified blend of equity and fixed-income investments. Furthermore, equity investments are
diversified across U.S. and non-U.S. stocks, as well as growth, value and small and large capitalizations. Investment risk is measured and monitored on an
ongoing basis through quarterly investment portfolio reviews, annual liability measurements, and periodic asset/liability studies.

We employ a building block approach in determining the long-term rate of return for plan assets. Historical markets are studied and long-term historical

relationships between equities and fixed-income are preserved consistent with the widely accepted capital market principle that assets with higher volatility
generate a greater return over the long run. Current market factors such as inflation and interest rates are evaluated before long-term capital market assumptions
are determined. The long-term portfolio return is established via a building block approach with proper consideration of diversification and rebalancing. Peer
data and historical returns are reviewed to check for reasonability and appropriateness.

In addition, we provide defined benefit post-retirement health care and life insurance benefits to some employees. Covered employees become eligible for

these benefits at retirement after meeting minimum age and service requirements. The projected future cost of providing post-retirement benefits, such as
healthcare and life insurance, is recognized as an expense as employees render services. In general, retiree health benefits are paid as covered expenses are
incurred.

Net pension benefit cost (in thousands) consisted of the following:

Service cost
Interest cost
Expected return on plan assets
Net amortization and deferral
Net pension benefit costs

Net post-retirement benefit cost (in thousands) consisted of the following:

Service cost
Interest cost
Unrecognized net (gain)/loss

Net post-retirement benefit costs

Year Ended 

December 31,
2021

2,855  $
2,619 
(5,688)
3,212 
2,998  $

2022

2,516  $
3,120 
(5,887)
2,249 
1,998  $

2020

2,253 
4,037 
(6,019)
3,127 
3,398 

Year Ended December 31,

2022

2021

2020

18  $
180 
(2,360)
(2,162) $

24  $
141 
(2,204)
(2,039) $

70 
584 
— 
654 

$

$

$

$

107

 
 
 
 
 
 
 
The changes in benefit obligations and plan assets (in thousands), as well as the funded status (in thousands) of our pension and post-retirement plans

were as follows:

Benefit obligation at January 1,

Service cost
Interest cost
Actuarial (gain) loss
Benefits paid
Other

Benefit obligation at December 31,
Fair value of plan assets at January 1,
Actual return on plan assets
Employer contributions
Benefits paid
Other

Fair value of plan assets at December 31,
Plan assets less than benefit obligations at December 31
recognized as liability for pension and other post-retirement
benefits

Pension Benefits

Post-retirement Benefits

2022

2021

2022

2021

144,251  $
2,516 
3,120 
(28,494)
(9,486)
340 
112,247  $
120,911  $
(22,507)
— 
(9,486)
1 
88,919  $

157,198  $
2,855 
2,619 
(6,637)
(9,551)
(2,233)
144,251  $
120,563  $
7,099 
2,800 
(9,551)
— 
120,911  $

9,391  $
18 
180 
(1,566)
(504)
58 
7,577  $
—  $
— 
446 
(504)
58 
—  $

11,318 
24 
141 
(3,193)
(680)
1,781 
9,391 
— 
— 
579 
(680)
101 
— 

(23,328) $

(23,340) $

(7,577) $

(9,391)

$

$
$

$

$

The accumulated benefit obligation for the defined benefit pension plans, which excludes the assumption of future salary increases, totaled $112.2 million

and $144.3 million at December 31, 2022 and 2021, respectively. We record components other than service costs in Other income, net, including interest
income in the Consolidated Statements of Operations.

We also sponsor unfunded, nonqualified pension plans. The projected benefit obligation, accumulated benefit obligation and fair value of plan assets for
these plans were $1.2 million, $1.2 million and zero, respectively, at December 31, 2022 and $1.5 million, $1.5 million and zero, respectively, at December 31,
2021.

Future estimated annual benefit payments (in thousands) for pension and post-retirement benefit obligations were as follows:

2023
2024
2025
2026
2027
2028-2032

Pension

$

Benefits

Before
Medicare
Subsidy

Post-retirement

After
Medicare
Subsidy

9,489  $
9,466 
9,323 
9,250 
9,072 
42,390 

996  $
942 
844 
791 
729 
2,715 

996 
942 
844 
791 
729 
2,715 

Our best estimate of expected contributions to the pension and post-retirement medical benefit plans for the 2023 fiscal year are zero and $1.0 million,

respectively.

108

 
 
 
 
 
 
 
 
 
 
The total amounts in accumulated other comprehensive income (loss) related to net actuarial loss for the pension and post-retirement plans were $6.5
million and $10.2 million as of December 31, 2022 and 2021, respectively. The total amounts in accumulated other comprehensive income (loss) related to prior
service cost for the pension and post-retirement plans, were gains of $5.4 million and $7.8 million as of December 31, 2022 and 2021, respectively.

The actuarial gains in 2022 and 2021 were primarily driven by the change in discount rates on the U.S. qualified plan and postretirement medical plans.

The impact of the discount rate change was partially offset by the actual return on plan assets exceeding the expected return on plan assets.

The following weighted-average assumptions were used to determine our obligations under the plans:

Discount rate
Long-term rate of compensation increase
Long-term rate of return on plan assets
Health care cost trend rate:

Pre-65 initial rate/ultimate rate
Pre-65 ultimate year
Post-65 initial rate/ultimate rate
Post-65 ultimate year

Pension Benefits

Post-retirement Benefits

2022

2021

2022

2021

5.2 %
N/A
6.0 %

N/A
N/A
N/A
N/A

2.8 %
N/A
5.8%

N/A
N/A
N/A
N/A

5.1 %
N/A
N/A

6.8%/4.5%
2031
N/A/N/A
N/A

2.6 %
N/A
N/A

6.2%/4.5%
2028
N/A/N/A
N/A

The weighted average discount rates used to determine the projected pension and post-retirement obligations were updated to reflect the expected long-

term rates of return with maturities comparable to payments for the plan obligations utilizing Aon Hewitt's AA Above Medium Curve.

Mortality tables used for pension benefits and post-retirement benefits plans were the following:

Pension and Post-retirement Benefits

2022

2021

Healthy Lives

Disabled Lives

Pri-2012 base mortality tables with generational
mortality improvements using Scale MP-2021
Pri-2012 base mortality tables with generational
mortality improvements using Scale MP-2021

Pri-2012 base mortality tables with generational
mortality improvements using Scale MP-2021
Pri-2012 base mortality tables with generational
mortality improvements using Scale MP-2021

The major investment categories and their relative percentage of the fair value of total plan assets as invested were as follows:

Equity securities
Debt securities
Cash

Pension Benefits

Post-retirement Benefits

(1)

2022

2021

2022

2021

54.3 %
44.2 %
1.5 %

51.6 %
46.1 %
2.3 %

— %
— %
— %

— %
— %
— %

(1)

Retiree health benefits are paid by the Company as covered expenses are incurred.

109

 
 
 
 
 
 
 
 
 
The fair values of the pension plan assets (in thousands) at December 31, 2022, by asset category, were as follows:

Cash and cash equivalents
Mutual funds:

Diversified emerging markets
Foreign large blend
Large-cap blend
Mid-cap blend

       Real Assets
Fixed income securities:

Corporate notes and bonds
U.S. Treasuries
Mortgage-backed securities
Asset-backed securities

Net asset

Level 1

Level 2

Level 3

Total

$

—  $

1,362  $

—  $

4,221 
16,740 
15,464 
7,720 
4,144 

27,892 
5,223 
— 
— 
81,404  $

$

— 
— 
— 
— 
— 

— 
— 
3,000 
3,153 
7,515  $

— 
— 
— 
— 
— 

— 
— 
— 
— 
—  $

1,362 

4,221 
16,740 
15,464 
7,720 
4,144 

27,892 
5,223 
3,000 
3,153 
88,919 

The fair values of the pension plan assets (in thousands) at December 31, 2021, by asset category, were as follows:

Cash and cash equivalents
Mutual funds:

Diversified emerging markets
Foreign large blend
Large-cap blend
Mid-cap blend
Real estate

Fixed income securities:

Corporate notes and bonds
U.S. Treasuries
Mortgage-backed securities
Asset-backed securities
Real Assets

Net asset

Level 1

Level 2

Level 3

Total

$

—  $

2,743  $

—  $

6,375 
21,719 
22,907 
11,411 
— 

35,365 
6,915 
— 
— 
— 
104,692  $

$

— 
— 
— 
— 
— 

— 
— 
2,242 
1,739 
9,495 
16,219  $

— 
— 
— 
— 
— 

— 
— 
— 
— 
— 
—  $

2,743 

6,375 
21,719 
22,907 
11,411 
— 

35,365 
6,915 
2,242 
1,739 
9,495 
120,911 

We contribute to three multiemployer defined benefit pension plans under the terms of collective-bargaining agreements for union-represented

employees. A multiemployer plan is subject to collective bargaining for employees of two or more unrelated companies. These plans allow multiple employers
to pool their pension resources and realize efficiencies associated with the daily administration of the plan. Multiemployer plans are generally governed by a
board of trustees composed of management and labor representatives and are funded through employer contributions. However, in most cases, management is
not directly represented.

The risks of participating in multiemployer plans differ from single employer plans as follows: 1) assets contributed to a multiemployer plan by one
employer may be used to provide benefits to employees of other participating employers, 2) if a participating employer stops contributing to the plan, the
unfunded obligations of the plan may be borne by the remaining participating employers, and 3) if we cease to have an obligation to contribute to one or more
of the multiemployer plans to which we contribute, we may be required to pay those plans an amount based on the underfunded status of the plan, referred to as
a withdrawal liability.

110

A summary of each multiemployer pension plan for which we participate is presented below:

Pension
Fund
LIUNA
IUOE
CSSS

(2)

EIN/ Pension
Plan No.

52-6074345/001
36-6052390/001
36-6044243/001

Pension Protection Act
Zone Status

(1)

2022
Green
Green
Red

2021
Green
Green
Red

FIP/RP  Status
Pending/
Implemented
No
No
Yes

Company
Contributions
(in thousands)

2022

2021

2020

$

395  $
376 
51 

378  $
328 
51 

361 
256 
51 

Surcharge
Imposed
No
No
NA

Expiration
Date of
CBA
6/7/2025
8/1/2027
NA

(1)

(2)

The Pension Protection Act of 2006 defines the zone status as follows: green—healthy, yellow—endangered, orange—seriously endangered and red—
critical.
In 2011, we withdrew from the Central States, Southeast and Southwest Areas Pension Plan. The withdrawal liability of $1.0 million will be paid in
monthly installments of $4,000 until 2031.

Our contributions to individual multiemployer pension funds did not exceed 5% of the fund’s total contributions for the years ended December 31, 2022,

2021 and 2020. Additionally, our contributions to multiemployer post-retirement benefit plans were immaterial for all periods presented in the accompanying
consolidated financial statements.

We also sponsor a defined contribution plan covering certain employees. We contribute to the plan in two ways. For certain employees not covered by the

defined benefit plan, we make a contribution equal to 4% of their salary. For all other eligible employees, we make a contribution of up to 6% of eligible
earnings. Contributions were $6.9 million, $5.9 million and $4.4 million for the years ended December 31, 2022, 2021 and 2020, respectively.

NOTE R— LEASES

We lease railroad cars, office space, mining property, mining/processing equipment, and transportation and other equipment. The majority of our leases
have remaining lease terms of approximately one year to 20 years. Our lease terms may include options to extend or terminate the lease when it is reasonably
certain that we will exercise that option. We have lease agreements with lease and non-lease components, the latter of which are generally accounted for
separately.

Supplemental balance sheet information related to leases (in thousands except for term and rate information) was as follows:

Leases

Classification

December 31, 2022

December 31, 2021

Assets
Operating
Finance

     Total leased assets
Liabilities
Current
Operating
Finance
Non-Current
Operating
Finance

     Total lease liabilities

Lease right-of-use assets
Lease right-of-use assets

Current portion of operating lease liabilities
Current portion of long-term debt

Operating lease liabilities
Long-term debt, net

$

$

$

$

39,088  $
3,286 
42,374  $

19,773  $
1,107 

64,478 
2,153 
87,511  $

38,793 
3,448 
42,241 

14,469 
1,061 

75,130 
2,485 
93,145 

Operating lease liabilities are based on the net present value of the remaining lease payments over the remaining lease term. As most of our leases do not

provide an implicit rate, in determining the lease liability and the present value of lease payments, we used our incremental borrowing rate based on the
information available at the lease commencement date. The weighted average remaining lease term and discount rate related to leases were as follows:

Lease Term and Discount Rate
Weighted average remaining lease term:
     Operating leases
     Finance leases

Weighted average discount rate:
     Operating leases
     Finance leases

December 31, 2022

December 31, 2021

6.4 years
4.4 years

5.7 %
5.1 %

6.9 years
3.6 years

5.7 %
5.1 %

The components of lease expense included in our Consolidated Statements of Operations were as follows:

Lease Costs
 (1)

Operating lease costs
Operating lease costs 

(2)

Total 

(3)

Classification

December 31, 2022

December 31, 2021

Cost of Sales
Selling, general, and administrative

$

$

38,576  $
1,641 
40,217  $

33,185 
1,880 
35,065 

Year Ended 

Year Ended 

(1)

(2)

(3) 

 Included short-term operating lease costs of $23.5 million and $17.9 million for the years ended December 31, 2022 and 2021, respectively.
 Included short-term operating lease costs of $0.5 million and $0.4 million for the years ended December 31, 2022 and 2021, respectively.
Does not include expense of $1.5 million and $0.8 million for the years ended December 31, 2022 and 2021 for finance leases.

Supplemental cash flow information related to leases was as follows:

 
 
 
 
 
 
 
 
 
 
Cash paid for amounts included in the measurement of lease liabilities:
     Operating cash flows for operating leases
     Financing cash flows for finance leases

Right-of-use assets obtained in exchange for new lease liabilities:
     Operating leases
     Finance leases

Maturities of lease liabilities as of December 31, 2022:

Year Ended December 31, 2022 Year Ended December 31, 2021

$
$

$
$

22,410  $
1,576  $

14,744  $
2,536  $

24,451 
759 

17,350 
3,815 

Maturities of lease liabilities
2023
2024
2025
2026
2027
Thereafter
     Total lease payments
Less: Interest
Less: Other operating expenses

     Total

Operating leases

Finance leases

$

$

$

24,707  $
20,230 
14,725 
11,812 
8,281 
23,701 
103,456  $
16,715 
2,490 
84,251  $

1,249 
1,123 
842 
271 
33 
— 
3,518 
258 
— 
3,260 

NOTE S— INCOME TAXES

We evaluate our deferred tax assets periodically to determine if valuation allowances are required. Ultimately, the realization of deferred tax assets is

dependent upon generation of future taxable income during those periods in which temporary differences become deductible and/or credits can be utilized. To
this end, management considers the level of historical taxable income, the scheduled reversal of deferred tax liabilities, tax-planning strategies and projected
future taxable income. Based on these considerations, and the carry-forward availability of a portion of the deferred tax assets, management believes it is more
likely than not that we will realize the benefit of the deferred tax assets.

On March 27, 2020, the Coronavirus Aid, Relief, and Economic Security Act ("CARES" Act) was enacted and signed into law in response to the

COVID-19 pandemic. The CARES Act, among other things, permitted NOL carryovers and carrybacks to offset 100% of taxable income for taxable years
beginning after 2017 and before 2021. In addition, the CARES Act allowed NOLs generated after 2017 and before 2021 to be carried back to each of the five
preceding taxable years to generate a refund of previously paid income taxes. As a result, during 2020, we carried the NOL generated in 2019 back to offset the
taxable income in the 2014 tax year generating a refund of $36.6 million. This refund was received during the second quarter of 2020. We also amended our
2018 tax return to generate an NOL by electing bonus depreciation. We then carried the NOL generated in 2018 back to offset the taxable income in prior years
generating a refund of $26.3 million, of which $4.9 million was received during the fourth quarter of 2020 and $21.1 million was received during the first
quarter of 2022. At December 31, 2022, the remaining $0.3 million of this refund was included in our deferred tax asset balance. The deferred tax assets related
to the NOLs generated in 2018 and 2019 were recorded at the statutory income tax rate for 2018 and 2019, which was 21% for both years. As a result of the
carry back of these NOLs to prior years, the NOLs will be utilized at the statutory income tax rate for pre-2018, which was 35%. This increase in the tax rate at
which the 2018 and 2019 NOLs will be utilized results in a deferred tax benefit. Accordingly, for the year ended December 31, 2020, we recorded a deferred tax
benefit of $22.3 million. Pursuant to ASC 740, this was recorded as a discrete component of the tax benefit.

Income (loss) before income taxes (in thousands) consisted of the following:

United States
Foreign

Total

Year ended December 31,

2022

2021

2020

$

$

87,686  $
16,313 
103,999  $

(48,328) $
11,252 
(37,076) $

(183,656)
8,509 
(175,147)

111

Income tax (expense) benefit (in thousands) consisted of the following: 

Current:

Federal
State
Foreign

Deferred:

Federal
State
Foreign

Income tax (expense) benefit

Year ended December 31,

2022

2021

2020

$

$

(1,650) $
(3,078)
(491)
(5,219)

(17,881)
(3,059)
— 
(20,940)
(26,159) $

—  $

(3,353)
(1,385)
(4,738)

7,589 
(96)
— 
7,493 
2,755  $

— 
(307)
(1,473)
(1,780)

57,214 
4,591 
— 
61,805 
60,025 

Income tax (expense) benefit (in thousands) differed from the amount that would be provided by applying the U.S. federal statutory rate due to the

following: 

Income tax (expense) benefit computed at U.S. federal statutory rate
Decrease (increase) resulting from:

Statutory depletion
Prior year tax return reconciliation
State income taxes, net of federal benefit
Impact of international operations
Unrecognized tax benefits
Adjustment to deferred taxes from the CARES Act
Equity compensation
Executive compensation
Other, net
Income tax (expense) benefit

Year ended December 31,

2022

2021

2020

$

(21,838) $

7,786  $

2,963 
(1,564)
(4,003)
(830)
(89)
— 
(195)
(300)
(303)
(26,159) $

$

2,012 
(2,490)
445 
(380)
(1,302)
— 
(627)
(2,092)
(597)
2,755  $

36,781 

1,230 
(2,084)
5,013 
(795)
— 
22,318 
(1,477)
(579)
(382)
60,025 

Deferred tax assets and liabilities are recognized for the estimated future tax effects, based on enacted tax laws, of temporary differences between the

values of assets and liabilities recorded for financial reporting and for tax purposes and of net operating loss and other carryforwards.

112

 
 
 
The tax effects of the types of temporary differences and carry forwards that gave rise to deferred tax assets and liabilities (in thousands) consisted of the

following:

Gross deferred tax assets:

Net operating loss carry forward and state tax credits
Pension and post-retirement benefit costs
Property, plant and equipment
Accrued expenses
Inventories
Federal tax credits
Stock-based compensation expense
Interest expense limitation
Intangibles
Lease obligation liability
Other

Total deferred tax assets

Gross deferred tax liabilities:

Land and mineral property basis difference
Fixed assets and depreciation
Inventories
Other

Total deferred tax liabilities

Net deferred tax liabilities

December 31,

2022

2021

$

54,638  $
6,789 
5,935 
18,232 
— 
1,047 
6,374 
19,826 
6,366 
11,393 
5,886 
136,486 

(124,669)
(74,714)
(1,170)
(569)
(201,122)

$

(64,636) $

77,327 
7,318 
8,619 
14,930 
1,200 
4,188 
4,359 
16,921 
7,876 
13,297 
4,399 
160,434 

(121,211)
(83,708)
— 
(289)
(205,208)
(44,774)

We have federal net operating loss carry forwards of approximately $215.8 million at December 31, 2022. A portion of those losses are subject to an

annual limitation under Internal Revenue Code Section 382, but are expected to be fully realized. NOL deductions generated in tax years after December 31,
2017 can offset 100% of taxable income for periods prior to 2021 but only 80% of taxable income after 2020. The CARES Act also prohibits NOL carrybacks
on NOLs generated after December 31, 2020 but allows indefinite carryforwards. As of December 31, 2022, we have general business credits of approximately
$1.0 million, which will expire beginning in 2033. These credits are expected to be fully realized.

The following table is a reconciliation of our unrecognized tax benefits (in thousands):

Balance as of January 1
Additions for tax positions of prior years

       Balance as of December 31

$

$

856  $
— 
856  $

—  $
856 
856  $

— 
— 
— 

Year ended December 31,

2022

2021

2020

If the unrecognized tax benefits of $0.9 million are realized, this would negatively impact the effective tax rate. As of December 31, 2022, 2021 and
2020, we had approximately $0.5 million, $0.4 million, and zero, respectively, of interest and penalties related to uncertain tax positions. During 2022, 2021 and
2020, we accrued and recognized estimated interest and penalties related to uncertain tax positions of approximately $0.1 million, $0.4 million and zero,
respectively. We include potential interest and penalties related to uncertain tax positions in the income tax (expense)/benefit line item in our Consolidated
Statements of Operations. We do not expect a significant change to the unrecognized tax benefits during the next twelve months. Tax returns filed with the IRS
for the years 2019 through 2021 along with tax returns filed with numerous state entities remain subject to examination.

113

 
 
NOTE T— REVENUE

We consider sales disaggregated at the product and service level by business segment to depict how the nature, amount, timing and uncertainty of

revenues and cash flow are impacted by changes in economic factors. The following table reflects our sales disaggregated by major source (in thousands):

Category
Product
Service

Total Sales

Oil & Gas
Proppants

Year Ended December 31, 2022
Industrial &
Specialty Products

Total Sales

$

$

576,293  $
385,374 
961,667  $

563,480  $
— 
563,480  $

1,139,773  $
385,374 
1,525,147  $

Oil & Gas Proppants
407,772 
207,676 
615,448 

Year Ended December 31, 2021
Industrial &
Specialty Products
488,431 
$
— 
488,431 

$

$

$

Total Sales

896,203 
207,676 
1,103,879 

The following tables reflect the changes in our contract assets, which we classify as unbilled receivables and our contract liabilities, which we classify as

deferred revenues (in thousands):

Beginning Balance
Reclassifications to billed receivables
Revenues recognized in excess of period billings
Ending Balance

Unbilled Receivables

December 31, 2022

December 31, 2021

$

$

1,957  $
(4,457)
2,500 

—  $

47,982 
(105,305)
59,280 
1,957 

We enter into certain customer supply agreements which give the customers the right to purchase certain products for a discounted price at certain
volumes over an average initial contract term of one to fifteen years. The advance payments represent future purchases and are recorded as deferred revenue,
recognized as revenue over the contract term of each supply agreement.

Beginning Balance
Revenues recognized from balances held at the beginning of the period
Revenues deferred from period collections on unfulfilled performance obligations
Revenues recognized from period collections
Ending Balance

Deferred Revenue

December 31, 2022

December 31, 2021

$

$

20,741  $
(3,905)
27,398 
(13,482)
30,752  $

33,692 
(13,172)
5,207 
(4,986)
20,741 

We have elected to use the practical expedients allowed under ASC 606-10-50-14, pursuant to which we have excluded disclosures of transaction prices

allocated to remaining performance obligations and when we expect to recognize such revenue. The majority of our remaining performance obligations are
primarily comprised of unfulfilled product, transportation service, and labor service orders, all of which hold a remaining duration of less than one year. The
long term portion of deferred revenue primarily represents a combination of refundable and nonrefundable customer prepayments for which
related current performance obligations do not yet exist, but are expected to arise, before the expiration of the contract. Our residual unfulfilled performance
obligations are comprised primarily of long-term equipment rental arrangements in which we recognize revenues equal to what we have a right to invoice.
Generally, no variable consideration exists related to our remaining performance obligations and no consideration is excluded from the associated transaction
prices. However, the changes in the deferred revenue balance are partially attributable to revenue recognized as variable consideration from shortfall fees
assessed to multiple customers according to contract terms as of December 31, 2022 and 2021. For the years ended December 31, 2022 and 2021, we
recognized revenue as variable consideration from shortfall fees according to contract terms in the amounts of $1.1 million and $49.7 million, respectively. We
believe these amounts are the best estimates of revenue to recognize as of year end.

During the second quarter of 2021, we entered into an agreement to settle a customer dispute regarding fees related to minimum purchase commitments

from 2014-2020. As a result of this settlement, we recognized approximately $49.0 million in revenue as of June 30, 2021. These amounts were received in full
during the second and third quarters of 2021.

114

Foreign Operations

The following table includes information related to our foreign operations (in thousands):

December 31, 2022

For the years ended
December 31, 2021

December 31, 2020

Total Sales
Pre-tax income
Net income

$
$
$

112,753  $
16,313  $
12,887  $

96,317  $
11,252  $
8,889  $

86,179 
8,509 
6,722 

Foreign operations constituted approximately $33.4 million and $30.7 million of consolidated assets as of December 31, 2022 and 2021, respectively.

NOTE U— RELATED PARTY TRANSACTIONS

There were no related party transactions during the years ended December 31, 2022, 2021 or 2020.

NOTE V— SEGMENT REPORTING

Our business is organized into two reportable segments, Oil & Gas Proppants and Industrial & Specialty Products, based on end markets. The reportable
segments are consistent with how management views the markets that we serve and the financial information reviewed by the chief operating decision maker.
We manage our Oil & Gas Proppants and Industrial & Specialty Products businesses as components of an enterprise for which separate information is available
and is evaluated regularly by the chief operating decision maker in deciding how to allocate resources and assess performance.

In the Oil & Gas Proppants segment, we serve the oil and gas recovery market primarily by providing and delivering fracturing sand, or “frac sand,”

which is pumped down oil and natural gas wells to prop open rock fissures and increase the flow rate of oil and natural gas from the wells.

The Industrial & Specialty Products segment consists of over 600 product types and materials used in a variety of markets including building and

construction products, fillers and extenders, filtration, glassmaking, absorbents, foundry, and sports and recreation.

An operating segment’s performance is primarily evaluated based on segment contribution margin, which excludes selling, general, and administrative

costs, corporate costs, plant capacity expansion expenses, and facility closure costs. We believe that segment contribution margin, as defined above, is an
appropriate measure for evaluating the operating performance of our segments. However, segment contribution margin is a non-GAAP measure and should be
considered in addition to, not a substitute for, or superior to, net income (loss) or other measures of financial performance prepared in accordance with GAAP.
The other accounting policies of each of the two reportable segments are the same as those in Note B - Summary of Significant Accounting Policies to these
Consolidated Financial Statements.

115

The following table presents sales and segment contribution margin (in thousands) for the reportable segments and other operating results not allocated to

the reported segments:

Sales:

Oil & Gas Proppants
Industrial & Specialty Products

Total sales
Segment contribution margin:
Oil & Gas Proppants
Industrial & Specialty Products

Total segment contribution margin

Operating activities excluded from segment cost of sales
Selling, general and administrative
Depreciation, depletion and amortization
Goodwill and other asset impairments
Interest expense
Other income, net, including interest income
Income tax (expense) benefit

Net income (loss)

Less: Net loss attributable to non-controlling interest

Net income (loss) attributable to U.S. Silica Holdings, Inc.

Year Ended 

December 31,

2021

2020

2022

$

961,667  $
563,480 
1,525,147 

615,448  $
488,431 
1,103,879 

301,837 
170,280 
472,117 
(17,159)
(143,838)
(140,166)
— 
(77,598)
10,643 
(26,159)
77,840  $
(336)
78,176  $

$

$

160,052 
168,499 
328,551 
(19,655)
(119,628)
(161,131)
(202)
(71,157)
6,146 
2,755 
(34,321) $
(560)
(33,761) $

414,897 
430,988 
845,885 

142,041 
159,176 
301,217 
(30,402)
(124,171)
(155,568)
(110,688)
(79,885)
24,350 
60,025 
(115,122)
(1,028)
(114,094)

Asset information, including capital expenditures and depreciation, depletion, and amortization, by segment is not included in reports used by

management in its monitoring of performance and, therefore, is not reported by segment. At both December 31, 2022 and 2021, goodwill of $185.6 million has
been allocated to these segments with zero assigned to Oil & Gas Proppants and $185.6 million to Industrial & Specialty Products.

116

 
 
 
 
 
 
NOTE W— PARENT COMPANY FINANCIALS

U.S. SILICA HOLDINGS, INC.

(PARENT COMPANY ONLY)

CONDENSED BALANCE SHEETS

2022

December 31,

(in thousands)

2021

ASSETS

48,398 
275 
160,315 
208,988 
495,776 
704,764 

50 
20 
70 
70 

— 
854 
1,234,834 
(351,084)
(186,196)
(1,723)
696,685 
8,009 
704,694 
704,764 

$

$

$

$

46,996 
— 
165,632 
212,628 
401,691 
614,319 

50 
186 
236 
236 

— 
845 
1,218,575 
(429,260)
(186,294)
349 
604,215 
9,868 
614,083 
614,319 

Current Assets:

Cash and cash equivalents
Other receivables
Due from affiliates

Total current assets

Investment in subsidiaries

Total assets

$

$

LIABILITIES AND STOCKHOLDERS’ EQUITY

Current Liabilities:

Accounts payable and accrued liabilities
Dividends payable

Total current liabilities
Total liabilities
Stockholders’ Equity:
Preferred stock
Common stock
Additional paid-in capital
Retained deficit
Treasury stock, at cost
Accumulated other comprehensive (loss) income

Total U.S. Silica Holdings, Inc. stockholders’ equity
Non-controlling interest
Total stockholders' equity

Total liabilities and stockholders’ equity

$

$

117

 
 
U.S. SILICA HOLDINGS, INC.

(PARENT COMPANY ONLY)

CONDENSED STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME (LOSS)

Sales
Cost of sales
Operating expenses

Selling, general and administrative

Total operating expenses

Operating loss
Other income (expense)
Interest income

Total other income

Income (loss) before income taxes and equity in net earnings of subsidiaries

Income tax expense

Income (loss) before equity in net earnings of subsidiaries

Equity in earnings of subsidiaries, net of tax

Net income (loss)

Less: Net loss attributable to non-controlling interest

Net income (loss) attributable to U.S. Silica Holdings, Inc.

Net income (loss)
Other comprehensive (loss) income

Unrealized (loss) gain on derivatives (net of tax of $(746), $0, and $973 for 2022, 2021, and
2020, respectively)
Foreign currency translation adjustment (net of tax of $(269), $(309), and $444 for 2022,
2021 and 2020, respectively)
Pension and other post-retirement benefits liability adjustment (net of tax of $355, $3,131,
and $2,207 for 2022, 2021 and 2020, respectively)

Comprehensive income (loss)

Less: Comprehensive loss attributable to non-controlling interest

Comprehensive income (loss) attributable to U.S. Silica Holdings, Inc.

2022

Year ended December 31,

2021

(in thousands)

2020

—  $
— 

253 
253 
(253)

565 
565 
312 
— 
312 
77,528 
77,840  $
(336)
78,176  $

—  $
— 

252 
252 
(252)

5 
5 
(247)
— 
(247)
(34,074)
(34,321) $
(560)
(33,761) $

— 
— 

253 
253 
(253)

210 
210 
(43)
— 
(43)
(115,079)
(115,122)
(1,028)
(114,094)

77,840  $

(34,321) $

(115,122)

(2,342)

(845)

1,115 
75,768  $
(336)
76,104  $

— 

(1,000)

9,828 
(25,493) $
(560)
(24,933) $

3,053 

1,391 

6,931 
(103,747)
(1,028)
(102,719)

$

$

$

$

$

$

118

 
 
U.S. SILICA HOLDINGS, INC.

(PARENT COMPANY ONLY)

(amounts in thousands)

Par Value Treasury Stock

Additional
Paid-In Capital

Retained
Deficit -
Present

Accumulated Other
Comprehensive
(Loss) Income

Total U.S. Silica,
Inc. Stockholders'
Equity

Non-
controlling
Interest

Total
Stockholders’
Equity

CONDENSED STATEMENTS OF STOCKHOLDERS' EQUITY

Balance at January 1, 2020

$

Net loss
Unrealized gain on derivatives
Foreign currency translation adjustment
Pension and post-retirement liability
Cash dividend declared ($0.02 per share)
Contributions from non-controlling interest
Common stock-based compensation plans
activity:

Equity-based compensation
Shares withheld for employee taxes
related to vested restricted stock and
stock units

Balance at December 31, 2020

$

Net loss
Foreign currency translation adjustment
Pension and post-retirement liability
Cash dividends
Distributions to non-controlling interest
Common stock-based compensation plans
activity:

Equity-based compensation
Proceeds from options exercised
Shares withheld for employee taxes
related to vested restricted stock and
stock units

Balance at December 31, 2021

$

Net income (loss)
Unrealized loss on derivatives
Foreign currency translation adjustment
Pension and post-retirement liability
Cash dividends
Distributions to non-controlling interest
Common stock-based compensation plans
activity:

Equity-based compensation
Proceeds from options exercised
Shares withheld for employee taxes
related to vested restricted stock and
stock units

823  $
— 
— 
— 
— 
— 
— 

— 

4 

827  $
— 
— 
— 
— 
— 

— 
— 

18 

845  $
— 
— 
— 
— 
— 
— 

— 
— 

9 

(180,912) $

1,185,116  $

— 
— 
— 
— 
— 
— 

— 

— 
— 
— 
— 
— 
— 

14,911 

(703)

(4)

(181,615) $

1,200,023  $

— 
— 
— 
— 
— 

— 
344 

— 
— 
— 
— 
— 

18,809 
(239)

(5,023)

(18)

(186,294) $

1,218,575  $

— 
— 
— 
— 
— 
— 

— 
— 
— 
— 
— 
— 

(279,956) $
(114,094)
— 
— 
— 
(1,446)
— 

— 

— 

(395,496) $
(33,761)
— 
— 
(3)
— 

— 
— 

— 

(429,260) $
78,176 
— 
— 
— 
— 
— 

— 
3,051 

18,364 
(2,096)

(2,953)

(9)

— 
— 

— 

(19,854) $

— 
3,053 
1,391 
6,931 
— 
— 

— 

— 

(8,479) $
— 
(1,000)
9,828 
— 
— 

— 
— 

— 

349  $
— 
(2,342)
(845)
1,115 
— 
— 

— 
— 

— 

Balance at December 31, 2022

$

854  $

(186,196) $

1,234,834  $

(351,084) $

(1,723) $

705,217  $
(114,094)
3,053 
1,391 
6,931 
(1,446)
— 

14,911 

(703)

615,260  $
(33,761)
(1,000)
9,828 
(3)
— 

18,809 
105 

(5,023)

604,215  $
78,176 
(2,342)
(845)
1,115 
— 
— 

18,364 
955 

(2,953)

696,685  $

11,363  $
(1,028)
— 
— 
— 
— 
1,196 

— 

— 

11,531  $
(560)
— 
— 
— 
(1,103)

— 
— 

— 

9,868  $
(336)
— 
— 
— 
— 
(1,523)

— 
— 

— 

8,009  $

716,580 
(115,122)
3,053 
1,391 
6,931 
(1,446)
1,196 

14,911 

(703)

626,791 
(34,321)
(1,000)
9,828 
(3)
(1,103)

18,809 
105 

(5,023)

614,083 
77,840 
(2,342)
(845)
1,115 
— 
(1,523)

18,364 
955 

(2,953)

704,694 

119

 
 
U.S. SILICA HOLDINGS, INC.

(PARENT COMPANY ONLY)

CONDENSED STATEMENTS OF CASH FLOWS

Operating activities:

Net income (loss)
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating
activities:

Undistributed (income) loss from equity method investment, net

Changes in assets and liabilities, net of effects of acquisitions:

Other receivables
Accounts payable and accrued liabilities

Net cash provided by (used in) operating activities

Investing activities:

Investment in subsidiary

Net cash used in investing activities

Financing activities:
Dividends paid
Proceeds from options exercised
Tax payments related to shares withheld for vested restricted stock and stock units
(Distributions to) contributions from non-controlling interest
Net financing activities with subsidiaries

Net cash provided by (used in) financing activities

Net increase (decrease) in cash and cash equivalents
Cash and cash equivalents, beginning of period
Cash and cash equivalents, end of period

Supplemental cash flow information:
Cash received during the period for:

Interest

2022

Year ended December 31,
2021
(in thousands)

2020

$

77,840  $

(34,321) $

(115,122)

(77,528)

34,074 

115,079 

(275)
— 
37 

— 
— 

(164)
955 
(2,953)
(1,523)
5,050 
1,365 
1,402 
46,996 
48,398  $

— 
(236)
(483)

— 
— 

(26)
105 
(5,023)
(1,103)
6,675 
628 
145 
46,851 
46,996  $

— 
155 
112 

— 
— 

(6,185)
— 
(703)
1,196 
582 
(5,110)
(4,998)
51,849 
46,851 

(565) $

(17) $

(210)

$

$

Notes to Condensed Financial Statements of Registrant (Parent Company Only)

These condensed parent company only financial statements have been prepared in accordance with Rule 12-04, Schedule I of Regulation S-X, because
the restricted net assets of the subsidiaries of U.S. Silica Holdings, Inc. (as defined in Rule 4-08(e)(3) of Regulation S-X) exceed 25% of our consolidated net
assets. The ability of our operating subsidiaries to pay dividends may be restricted due to the terms of our Credit Facility, as discussed in Note K - Debt to these
financial statements.    

These condensed parent company financial statements have been prepared using the same accounting principles and policies described in the notes to the

consolidated financial statements; the only exceptions are that (a) the parent company accounts for its subsidiaries using the equity method of accounting, (b)
taxes are allocated to the parent from the subsidiary using the separate return method, and (c) intercompany loans are not eliminated. In the parent company
financial statements, our investment in subsidiaries is stated at cost plus equity in undistributed earnings of subsidiaries since the date of acquisition. These
condensed parent company financial statements should be read in conjunction with our consolidated financial statements and related notes thereto included
elsewhere in this report.

120

 
 
 
No cash dividends were paid to the parent by its consolidated entities for the years presented in the condensed financial statements.

NOTE X— IMPAIRMENTS

We recorded impairment charges (in thousands) for the following assets:

Description
Inventories, net
Property, plant and mine development, net
Operating lease right-of-use assets
Goodwill
Intangible assets, net

Total

2020 Impairments

December 31, 2022

December 31, 2021

December 31, 2020

$

$

—  $
— 
— 
— 
— 
—  $

—  $
164 
— 
— 
38 
202  $

6,837 
11,822 
3,406 
86,100 
2,523 
110,688 

During 2020, there was an unprecedented drop in global demand combined with the breakdown of the Organization of the Petroleum Exporting Countries

and other oil producing nations ("OPEC+") agreement to restrict oil production that led to one of the largest annual crude oil inventory builds in history. This
led to a sharp reduction in global crude oil prices. Containment measures and other economic, travel, and business disruptions caused by COVID-19 also
affected refinery activity and future demand for crude oil, and consequently, the services and products of our Oil & Gas Proppants segment. As a result of these
triggering events, we completed impairment assessments for our assets, including plant, property and mine development, right-of-use assets, inventories, and
other intangible assets.

Inventories, net

We recorded impairment charges primarily related to unused inventory at plants we idled. These charges related to the Oil & Gas Proppants segment and

are recorded in "Goodwill and other asset impairments" in the Consolidated Statements of Operations.

Property, plant and mine development

We estimated the future undiscounted net cash flows of certain asset groupings using estimates of proven and probable sand reserves, estimated future
sales prices (considering historical and current prices, price trends and related factors) and operating costs and anticipated capital expenditures. In the cases
where the undiscounted cash flows are less than the carrying value of the assets, we recognized an impairment loss equal to the amount by which the carrying
value exceeds the fair value of the assets. Impairment charges were recorded related primarily to our Kosse, Texas facility, which was idled. These charges
related to the Oil & Gas Proppants segment and are recorded in "Goodwill and other asset impairments" in the Consolidated Statements of Operations.

Operating lease right-of-use assets

We determined the fair value of the railcars primarily utilizing internally developed cash flow models and quoted market prices, discounted at an

appropriate weighted average cost of capital. As a result, we recognized impairment charges primarily related to various equipment leases and an office building
lease. These charges related mainly to the Oil & Gas Proppants segment and are recorded in "Goodwill and other asset impairments" in the Consolidated
Statements of Operations.

Goodwill

We performed a quantitative analysis and determined that the goodwill of our Oil & Gas Proppants reporting unit was impaired. We recognized goodwill

impairment charges during the first quarter of 2020. These impairment charges were recorded in the "Goodwill and other asset impairments" caption of our
Consolidated Statements of Operations. The fair value of our reporting units was determined using the discounted cash flow method.

121

Intangible assets, net

We recorded impairments of $1.1 million for trade names and $1.4 million for patents and intellectual property as of December 31, 2020, which was
recorded in the Industrial & Specialty Products segment as a result of the discontinuance of a minor product line. These charges were recorded in the "Goodwill
and other asset impairments" caption of our Consolidated Statements of Operations.

NOTE Y-SUBSEQUENT EVENTS

We evaluated subsequent events through the date the consolidated financial statements were available for issuance and did not identify any events

requiring disclosure.    

ITEM 9.

CHANGES IN AND DISAGREEMENTS WITH ACCOUNTANTS ON ACCOUNTING AND FINANCIAL DISCLOSURE

None. 

ITEM 9A.

CONTROLS AND PROCEDURES

Evaluation of Disclosure Controls and Procedures

Our management, with the participation of our Chief Executive Officer and Chief Financial Officer, evaluated the effectiveness of our disclosure controls
and procedures as of December 31, 2022. The term “disclosure controls and procedures,” as defined in Rules 13a-15(e) and 15d-15(e) under the Exchange Act,
means controls and other procedures of a company that are designed to ensure that information required to be disclosed by a company in the reports that it files
or submits under the Exchange Act is recorded, processed, summarized and reported, within the time periods specified in the SEC’s rules and forms. Disclosure
controls and procedures include, without limitation, controls and procedures designed to ensure that information required to be disclosed by a company in the
reports that it files or submits under the Exchange Act is accumulated and communicated to the company’s management, including its principal executive and
principal financial officers, as appropriate to allow timely decisions regarding required disclosure. Solely as a result of the changes we had to make to our
mining disclosures in our Form 10-K for the fiscal year ended December 31, 2021, our Chief Executive Officer and Chief Financial Officer concluded that our
disclosure controls and procedures were not effective as of December 31, 2021. To remediate this conclusion, during 2022 we engaged a new qualified person
to prepare our mining technical report studies and review the related mining disclosures. Because the omitted disclosures did not affect our financial statements,
no additional remediation was deemed necessary. Based on the evaluation of our disclosure controls and procedures as of December 31, 2022, our Chief
Executive Officer and Chief Financial Officer concluded that, as of such date, our disclosure controls and procedures were effective at the reasonable assurance
level.

Management recognizes that any controls and procedures, no matter how well designed and operated, can provide only reasonable, and not absolute,
assurance of achieving their objectives and management necessarily applies its judgment in evaluating the cost-benefit relationship of possible controls and
procedures.

Management’s Annual Report on Internal Control over Financial Reporting

Our management, under the direction of our Chief Executive Officer and Chief Financial Officer, is responsible for establishing and maintaining adequate

internal control over financial reporting as defined in Exchange Act Rule 13a-15(f).

Our system of internal control over financial reporting is designed to provide reasonable assurance to our management and Board of Directors regarding

the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting
principles in the United States of America.

Our management conducted an evaluation of the effectiveness of our internal control over financial reporting using the framework in 2013 Internal

Control—Integrated Framework issued by the Committee of Sponsoring Organizations of the Treadway Commission (COSO). As noted in the COSO
framework, an internal control system, no matter how well conceived and operated, can provide only reasonable, not absolute, assurance to management and
the Board of Directors regarding

122

achievement of an entity's financial reporting objectives. Based upon the evaluation under this framework, management concluded that our internal control over
financial reporting was effective as of December 31, 2022.

Our independent registered public accounting firm has audited the effectiveness of our internal control over financial reporting as of December 31, 2022,

as stated in its report below.

Changes in Internal Control over Financial Reporting

There were no changes in our internal control over financial reporting identified in management’s evaluation pursuant to Rules 13a-15(d) or 15d-15(d) of

the Exchange Act during the quarter ended December 31, 2022 that materially affected, or are reasonably likely to materially affect, our internal control over
financial reporting.

123

REPORT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

Board of Directors and Shareholders
U.S. Silica Holdings, Inc.

Opinion on internal control over financial reporting
We have audited the internal control over financial reporting of U.S. Silica Holdings, Inc. (a Delaware corporation) and subsidiaries (the “Company”) as of
December 31, 2022, based on criteria established in the 2013 Internal Control—Integrated Framework issued by the Committee of Sponsoring Organizations of
the Treadway Commission (“COSO”). In our opinion, the Company maintained, in all material respects, effective internal control over financial reporting as of
December 31, 2022, based on criteria established in the 2013 Internal Control—Integrated Framework issued by COSO.

We also have audited, in accordance with the standards of the Public Company Accounting Oversight Board (United States) (“PCAOB”), the consolidated
financial statements of the Company as of and for the year ended December 31, 2022, and our report dated February 24, 2023 expressed an unqualified opinion
on those financial statements.

Basis for opinion
The Company’s management is responsible for maintaining effective internal control over financial reporting and for its assessment of the effectiveness of
internal control over financial reporting, included in the accompanying Management’s Report on Internal Control over Financial Reporting. Our responsibility
is to express an opinion on the Company’s internal control over financial reporting based on our audit. We are a public accounting firm registered with the
PCAOB and are required to be independent with respect to the Company in accordance with the U.S. federal securities laws and the applicable rules and
regulations of the Securities and Exchange Commission and the PCAOB.

We conducted our audit in accordance with the standards of the PCAOB. Those standards require that we plan and perform the audit to obtain reasonable
assurance about whether effective internal control over financial reporting was maintained in all material respects. Our audit included obtaining an
understanding of internal control over financial reporting, assessing the risk that a material weakness exists, testing and evaluating the design and operating
effectiveness of internal control based on the assessed risk, and performing such other procedures as we considered necessary in the circumstances. We believe
that our audit provides a reasonable basis for our opinion.

Definition and limitations of internal control over financial reporting
A company’s internal control over financial reporting is a process designed to provide reasonable assurance regarding the reliability of financial reporting and
the preparation of financial statements for external purposes in accordance with generally accepted accounting principles. A company’s internal control over
financial reporting includes those policies and procedures that: (1) pertain to the maintenance of records that, in reasonable detail, accurately and fairly reflect
the transactions and dispositions of the assets of the company; (2) provide reasonable assurance that transactions are recorded as necessary to permit preparation
of financial statements in accordance with generally accepted accounting principles, and that receipts and expenditures of the company are being made only in
accordance with authorizations of management and directors of the company; and (3) provide reasonable assurance regarding prevention or timely detection of
unauthorized acquisition, use, or disposition of the company’s assets that could have a material effect on the financial statements.

Because of its inherent limitations, internal control over financial reporting may not prevent or detect misstatements. Also, projections of any evaluation of
effectiveness to future periods are subject to the risk that controls may become inadequate because of changes in conditions, or that the degree of compliance
with the policies or procedures may deteriorate.

GRANT THORNTON LLP

Houston, Texas
February 24, 2023

124

ITEM 9B.

OTHER INFORMATION

Not applicable. 

ITEM 9C.

DISCLOSURE REGARDING FOREIGN JURISDICTIONS THAT PREVENT INSPECTIONS

Not applicable.

ITEM 10.

DIRECTORS, EXECUTIVE OFFICERS AND CORPORATE GOVERNANCE

PART III

The information required by this item with respect to directors and corporate governance will be set forth under “Proposal No. 1: Election of Directors” in

the 2023 Proxy Statement and is incorporated herein by reference.

The information required by this item with respect to executive officers of U.S. Silica, pursuant to the instruction of Item 401 of Regulation S-K, is set

forth following Part I, Item 1. of this Annual Report on Form 10-K under “Executive Officers of the Registrant”. 

ITEM 11.

EXECUTIVE COMPENSATION

The information required by this item will be set forth under “Executive and Director Compensation” and “Report of Compensation Committee” in the

2023 Proxy Statement and is incorporated herein by reference.

ITEM 12.

SECURITY OWNERSHIP OF CERTAIN BENEFICIAL OWNERS AND MANAGEMENT AND RELATED STOCKHOLDER
MATTERS

The information required by Item 403 of Regulation S-K regarding security ownership of certain beneficial owners and management will be set forth

under “Stock Ownership” in the 2023 Proxy Statement and is incorporated herein by reference.

The information required by Item 201(d) of Regulation S-K regarding securities authorized for issuance under equity compensation plans is furnished as a

separate item captioned “Securities Authorized for Issuance Under Equity Compensation Plans” included in Part II, Item 5. of this Annual Report on Form 10-
K.

ITEM 13.

CERTAIN RELATIONSHIPS AND RELATED TRANSACTIONS, AND DIRECTOR INDEPENDENCE

The information required by this item will be set forth under “Transactions with Related Persons” and “Determination of Independence” in the 2023

Proxy Statement and is incorporated herein by reference.

ITEM 14.

PRINCIPAL ACCOUNTING FEES AND SERVICES

The information required by this item will be set forth under “Ratification of Grant Thornton LLP as Independent Registered Public Accounting Firm for

2023” in the 2023 Proxy Statement and is incorporated herein by reference.

125

ITEM 15.

EXHIBITS AND FINANCIAL STATEMENT SCHEDULES

The following documents are filed as a part of this report:

    Consolidated Financial Statements

PART IV.

The Consolidated Financial Statements, together with the report thereon of Grant Thornton LLP, dated February 24, 2023, are included as part of Item 8.

Financial Statements and Supplementary Data.

Report of Independent Registered Public Accounting Firm
Consolidated Balance Sheets as of December 31, 2022 and 2021
Consolidated Statements of Operations for the Years Ended December 31, 2022, 2021 and 2020
Consolidated Statements of Comprehensive Income for the Years Ended December 31, 2022, 2021 and 2020
Consolidated Statements of Stockholders’ Equity for the Years Ended December 31, 2022, 2021 and 2020
Consolidated Statements of Cash Flows for the Years Ended December 31, 2022, 2021 and 2020
Notes to the Consolidated Financial Statements

Page

79
80
81
82
83
85
87

    Financial Statement Schedules

Schedule I - Condensed Financial Information of Parent (U.S. Silica Holdings, Inc.) at December 31, 2022 and 2021 and for the years ended

December 31, 2022, 2021 and 2020 is included in Note W - Parent Company Financial Statements to the Consolidated Financial Statements, included as part of
Item 8. Financial Statements and Supplementary Data.

    Exhibits

The information called for by this Item is incorporated herein by reference from the Exhibit Index included in this Annual Report on Form 10-K.

Exhibit
Number

2.1#

3.1

3.2

4.1

4.2

10.1+

10.2+

EXHIBIT INDEX

Incorporated by Reference

Description

Form

File No.

Exhibit

Filing Date

Agreement and Plan of Merger, dated as of March 22, 2018,
by and among EP Acquisition Parent, Inc. US Silica
Company, Tranquility Acquisition Corp., EPMC Parent
LLC, as the Stockholders' Representative, and solely for the
purposes of Section 11.17, Golden Gate Private Equity, Inc.
Third Amended and Restated Certificate of Incorporation
of U.S. Silica Holdings, Inc., effective May 4, 2017.
Third Amended and Restated Bylaws of U.S. Silica
Holdings, Inc., effective May 4, 2017.
Specimen Common Stock Certificate.

Description of the Registrant's Securities Registered
Pursuant to Section 12 of the Exchange Act
Employment Agreement dated as of March 22, 2012 by
and between U.S. Silica Company and Bryan A. Shinn
Form of Nonqualified Stock Option Agreement.

10-Q

8-K

8-K

S-1/A

10-K

8-K

S-1/A

126

001-35416

001-35416

001-35416

333-175636

001-35416

001-35416

333-175636

2.1

3.1

3.2

4.1

4.2

10.1

10.17

April 24, 2018

May 10, 2017

May 10, 2017

December 7, 2011

February 25, 2020

March 22, 2012

August 29, 2011

 
Form of Indemnification Agreement.

S-1/A

333-175636

10.3+

10.4+

10.5+

10.6+

10.7+

10.8+

10.9+

10.10+

10.11

10.12

10.13+

10.14+

10.15+

10.16+

10.17+

10.18+

10.19+

Letter Agreement, dated as of December 27, 2011, by and
between William J. Kacal and U.S. Silica Holdings, Inc.

Letter Agreement, dated April 27, 2012, by and between
Peter Bernard and U.S. Silica Holdings, Inc.

Omnibus Amendment dated February 18, 2016 to Award
Agreements.
Form of Nonqualified Stock Option Agreement.

Amendment dated February 18, 2016 to Employment
Agreement by and between U.S. Silica Holdings, Inc. and
Bryan Shinn.

Omnibus Amendment dated November 3, 2016 to Award
Agreements.
Letter Agreement, effective August 15, 2017, by and
between Diane Duren and U.S. Silica Holdings, Inc.
Third Amended and Restated Credit Agreement, dated as of
May 1, 2018, by and among U.S. Silica Holdings, Inc.,
through its subsidiaries, USS Holdings, Inc., as guarantor,
and U.S. Silica Company, as borrower, and certain of U.S.
Silica’s subsidiaries as additional guarantors and BNP
Paribas, as administrative agent and the lenders named
therein.
Consent and Amendment Agreement, dated as of August 23,
2019, among U.S. Silica Company and BNP Paribas, as
administrative agent and the lenders named therein,
amending that certain Third Amended and Restated Credit
Agreement, dated as of May 1, 2018.
Form of Performance Share Unit Agreement (Adjusted Cash
Flow) Pursuant to the Amended and Restated U.S. Silica
Holdings, Inc. 2011 Incentive Compensation Plan
Form of Performance Share Unit Agreement (Relative TSR)
Pursuant to the Amended and Restated U.S. Silica Holdings,
Inc. 2011 Incentive Compensation Plan
Form of Restricted Stock Agreement Pursuant to the
Amended and Restated U.S. Silica Holdings, Inc. 2011
Incentive Compensation Plan.
Form of Restricted Stock Unit Agreement, pursuant to the
Amended and Restated U.S. Silica Holdings, Inc. 2011
Incentive Compensation Plan.
U.S. Silica Holdings, Inc. Amended and Restated Change in
Control Severance Plan, as amended and restated April 29,
2020.
Form of Performance Share Unit Agreement (Relative TSR)
Pursuant to the Amended and Restated U.S. Silica Holdings,
Inc. 2011 Incentive Compensation Plan
Letter Agreement, effective September 21, 2021, by and
between Sandra Rogers and U.S. Silica Holdings, Inc.

S-1/A

333-175636

8-K

8-K

10-K

8-K

10-K

8-K

001-35416

001-35416

001-35416

001-35416

001-35416

001-35416

8-K

001-35416

10-Q

10-Q

10-Q

10-Q

001-35416

001-35416

001-35416

001-35416

10-Q

001-35416

10-Q

001-35416

10.20

10.24

10.10

10.3

10.2

10.2

10.22

10.1

10.1

10.1

10.1

10.2

10.3

10.1

10.2

December 29, 2011

December 29, 2011

May 1, 2012

February 23, 2016

February 25, 2015

February 23, 2016

February 23, 2017

August 18, 2017

May 2, 2018

October 30, 2019

May 1, 2019

May 1, 2019

May 1, 2019

May 1, 2020

May 1, 2020

10-Q

10-K

001-35416

001-35416

10.1

10.19

April 30, 2021

February 25, 2022

127

 
 
 
 
 
 
10-Q

001-35416

10-Q

001-35416

10-Q

001-35416

8-K

001-35416

10.1

10.2

10.3

10.1

April 29, 2022

April 29, 2022

April 29 2022

May 13, 2022

10.20+

10.21+

10.22+

10.23+

21.1*

23.1*

23.2*
31.1*

31.2*

32.1*

32.2*

95.1*

96.1*

96.2*

96.3*

96.4*

101*

Form of Restricted Stock Unit Agreement Pursuant to the
Amended and Restated U.S. Silica Holdings, Inc. 2011
Incentive Compensation Plan
Form of Performance Share Unit Agreement (Relative TSR)
Pursuant to the Amended and Restated U.S. Silica Holdings,
Inc. 2011 Incentive Compensation Plan
Form of Performance Share Unit Agreement (Adjusted
Cash Flow) Pursuant to the Amended and Restated U.S.
Silica Holdings, Inc. 2011 Incentive Compensation Plan
Fourth Amended and Restated U.S. Silica Holdings, Inc.
2011 Incentive Compensation Plan, as amended and restated
May 12, 2022

List of subsidiaries of U.S. Silica Holdings, Inc.
Consent of Independent Registered Public Accounting
Firm.

Consent of Third Party Qualified Person
Rule 13a-14(a)/15(d)-14(a) Certification by Bryan A.
Shinn, Chief Executive Officer.

Rule 13a-14(a)/15(d)-14(a) Certification by Donald A.
Merril, Chief Financial Officer.

Section 1350 Certification by Bryan A. Shinn, Chief
Executive Officer.

Section 1350 Certification by Donald A. Merril, Chief
Financial Officer.

Mine Safety Disclosure.

Technical Report Summary, Ottawa Site, LaSalle County,
Illinois
Technical Report Summary, Colado Site, Pershing County,
Nevada
Technical Report Summary, Lamesa Site, Lamesa, Dawson
County, Texas
Technical Report Summary, Crane Site, Crane County,
Texas
101.INS XBRL Instance - the instance document does not
appear in the Interactive Data File because its XBRL tags
are embedded within the Inline XBRL document

101.SCH XBRL Taxonomy Extension Schema

101.CAL XBRL Taxonomy Extension Calculation

101.LAB XBRL Taxonomy Extension Labels

101.PRE XBRL Taxonomy Extension Presentation

101.DEF XBRL Taxonomy Extension Definition

104*

Cover Page from the Company's Annual Report on Form
10-K for the year ended December 31, 2020 formatted
Inline XBRL (and contained in Exhibit 101)

Schedules have been omitted pursuant to Item 601(b)(2) of Regulation S-K. We will furnish the omitted schedules to the Securities and Exchange
Commission upon request by the Commission.

#

128

+ Management contract or compensatory plan/arrangement
* Filed herewith

We will furnish to any of our stockholders a copy of any of the above exhibits upon the written request of such stockholder and the payment to U.S. Silica
Holdings, Inc. of the reasonable expenses incurred in furnishing such copy or copies.

129

ITEM 16.

FORM 10-K SUMMARY

Not applicable.

130

    Pursuant to the requirements of Section 13 or 15(d) of the Securities Exchange Act of 1934, the Registrant has duly caused this Report to be signed on its
behalf by the undersigned, thereunto duly authorized, this 24th day of February, 2023.

SIGNATURES

    Pursuant to the requirements of the Securities Exchange Act of 1934, this Report has been signed below by the following persons on behalf of the Registrant
and in the capacities and on the dates indicated.

U.S. Silica Holdings, Inc.

/s/ BRYAN A. SHINN
Name:  
Title:

Bryan A. Shinn
Chief Executive Officer

Name

Capacity

Chief Executive Officer and Director
(Principal Executive Officer)

Date

February 24, 2023

February 24, 2023

/S/ BRYAN A. SHINN

Bryan A. Shinn

/S/ DONALD A. MERRIL

Donald A. Merril

/S/ CHARLES SHAVER

Charles Shaver

/S/ PETER BERNARD

Peter Bernard

/s/ DIANE DUREN

Diane Duren

/S/ WILLIAM J. KACAL

William J. Kacal

/s/ SANDRA ROGERS

Sandra Rogers

Executive Vice President, Chief Financial Officer
(Principal Financial and Accounting Officer)

Chairman of the Board

February 24, 2023

February 24, 2023

February 24, 2023

February 24, 2023

February 24, 2023

Director

Director

Director

Director

S-1

 
  
 
  
 
 
  
 
 
  
 
  
 
  
 
Exhibit 21.1

Name
Hourglass Acquisition I, LLC

Preferred Rocks USS Inc.

Hourglass Holdings, LLC

USS Holdings, Inc.

U.S. Silica Company

Pennsylvania Glass Sand Corporation

The Fulton Land and Timber Company

Ottawa Silica Company

Ottawa Silica Company, Ltd.

Coated Sand Solutions, LLC

Cadre Services Inc.

Cadre Material Products, LLC

Fairchild Silica, LLC

Utica Silica, LLC

Tyler Silica Company

New Birmingham Resources, LLC

NBR Sand, LLC

NBR Maritime I, LLC

NBR Maritime II, LLC

Sandbox Enterprises, LLC

Oren Technologies, LLC

Sandbox Leasing, LLC

Sandbox Logistics, LLC

Sandbox Transportation, LLC
Mississippi Sand, LLC
Arcadia Sand, LLC
Boss Energy Resources, LLC
Seagraves Development, LLC
EP Minerals Holdings, Inc.
EP Acquisition, LLC
EP Management Corporation
EP Minerals, LLC
EP Engineered Clays Corporation
EP Minerals International S.A.S.
EP Minerals Europe Verwaltungs und Beteiligungs GmbH
EP Minerals Europe GmbH & Co. KG
EP Mexican Parent, Inc.
EP Minerals de Mexico S. de R.L. de C.V.
Celatom de Mexico S. de R.L. de C.V.
Kermit Pipeline, LLC (50% ownership)
Spruce Acquisition, LLC

Jurisdiction of Formation

Delaware

Delaware

Delaware

Delaware

Delaware

Delaware

Pennsylvania

Delaware

Quebec, Canada

Delaware

Delaware

Texas

Delaware

Delaware

Delaware

Texas

Texas

Texas

Texas

Texas

Texas

Texas

Texas
Texas
Missouri
Delaware
Delaware
Delaware
Delaware
Delaware
Delaware
Delaware
Delaware
France
Germany
Germany
Delaware
Mexico
Mexico
Texas
Delaware

 
                                                 Exhibit 23.1

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

We have issued our reports dated February 24, 2023, with respect to the consolidated financial statements and internal control over financial reporting included
in the Annual Report of U.S. Silica Holdings, Inc. on Form 10-K for the year ended December 31, 2022. We hereby consent to the incorporation by reference of
said reports in the Registration Statements of U.S. Silica Holdings, Inc. on Form S-3ASR (333-258323) and Forms S-8 (333-179480, 333-204062, 333-238198,
333-256389 and 333-265119).

/s/ Grant Thornton LLP

Houston, Texas
February 24, 2023

John T. Boyd Company
Mining and Geological Consultants

Chairman
James W. Boyd

President and CEO
John T. Boyd II

February 24, 2023
File: 3076.017

Subject:    CONSENT OF THIRD-PARTY
        QUALIFIED PERSON

Managing Director and COO
Ronald L. Lewis

Ladies and Gentlemen:

The John T. Boyd Company (“BOYD”) in connection with the filing of the U.S. Silica

Holdings, Inc. Annual Report on Form 10-K for the fiscal year ended December 31,

2022 and any amendments or supplements and/or exhibits thereto (collectively, the

“Form 10-K”), consent to:

•

•

•

•

the filing and use of the technical report summary titled “Technical Report
Summary, Silica Sand Resources and Reserves, Ottawa Operation, LaSalle
County, Illinois” (the “Ottawa Technical Report”), with an effective date of
December 31, 2022, as an exhibit to and referenced in the Form 10-K;

the filing and use of the technical report summary titled “Technical Report
Summary, Proppant Sand Resources and Reserves, Lamesa Operation,
Dawson County, Texas” (the “Lamesa Technical Report”), with an effective date
of December 31, 2022, as an exhibit to and referenced in the Form 10-K;

the filing and use of the technical report summary titled “Technical Report
Summary, Proppant Sand Resources and Reserves, Crane Operation, Crane
County, Texas” (the “Crane Technical Report”), with an effective date of
December 31, 2022, as an exhibit to and referenced in the Form 10-K;

the filing and use of the technical report summary titled “Technical Report
Summary, Diatomaceous Earth Resources and Reserves, Colado Operation,
Pershing County, Nevada” (the “Colado Technical Report” and together with the
Ottawa Technical Report, Lamesa Technical Report, and Crane Technical
Report, the “Technical Reports”), with an effective date of December 31, 2022,
as an exhibit to and referenced in the 
Form 10-K;

Vice Presidents
Robert J. Farmer
John L. Weiss
Michael F. Wick
William P. Wolf

Managing Director - Australia
Jacques G. Steenkamp

Managing Director - China
Jisheng (Jason) Han

Managing Director – South America
Carlos F. Barrera

Managing Director – Metals
Gregory B. Sparks

Pittsburgh
4000 Town Center Boulevard, Suite 300
Canonsburg, PA 15317
(724) 873-4400
(724) 873-4401 Fax
jtboydp@jtboyd.com

Denver
(303) 293-8988
jtboydd@jtboyd.com

Brisbane
61 7 3232-5000
jtboydau@jtboyd.com

Beijing
86 10 6500-5854
jtboydcn@jtboyd.com

Bogota
+57-3115382113
jtboydcol@jtboyd.com

www.jtboyd.com

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
        2

•

•

the use of and references to our name, including our status as an expert or “qualified person” (as defined in Subpart 1300 of
Regulation S-K promulgated by the Securities and Exchange Commission), in connection with the Form 10-K and any such
Technical Report; and

the information derived, summarized, quoted or referenced from any of the Technical Reports, or portions thereof, that was
prepared by BOYD, that BOYD supervised the preparation of and/or that was reviewed and approved by BOYD, that is included
or incorporated by reference in the Form 10-K.

BOYD is responsible for authoring, and this consent pertains to, the Technical Reports. BOYD certifies that it has read the Form 10-

K and that it fairly and accurately represents the information in the sections of the Technical Reports for which BOYD is responsible.

BOYD also consents to the incorporation by reference in U.S. Silica Holdings, Inc.’s registration statements on Form S-8 (Nos. 333-

265119, 333-256389, 333-238198, 333-204062, 333-179480) and Form S-3ASR (No.333-258323) of the above items as included in

the Form 10-K.

Respectfully submitted,

JOHN T. BOYD COMPANY
By: /s/ John T. Boyd

John T. Boyd II
President and CEO

    JOHN T. BOYD COMPANY

Exhibit 31.1

I, Bryan A. Shinn, certify that:

CERTIFICATION

1.

2.

3.

4.

I have reviewed this Annual Report on Form 10-K of U.S. Silica Holdings, Inc. (the “Company”) for the year ended December 31, 2022;

Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the
statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this
report;

Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects the
financial condition, results of operations and cash flows of the registrant as of, and for, the periods presented in this report;

The registrant’s other certifying officer and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in
Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal control over financial reporting (as defined in Exchange Act Rules 13a-15(f) and 15d-
15(f)) for the registrant and have:

a)

b)

c)

d)

Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our
supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to
us by others within those entities, particularly during the period in which this report is being prepared;

Designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under
our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial
statements for external purposes in accordance with generally accepted accounting principles;

Evaluated the effectiveness of the registrant’s disclosure controls and procedures and presented in this report our conclusions about
the effectiveness of the disclosure controls and procedures, as of the end of the period covered by this report based on such
evaluation; and

Disclosed in this report any change in the registrant’s internal control over financial reporting that occurred during the registrant’s
most recent fiscal quarter (the registrant’s fourth fiscal quarter in the case of an annual report) that has materially affected, or is
reasonably likely to materially affect, the registrant’s internal control over financial reporting; and

5.

The registrant’s other certifying officer and I have disclosed, based on our most recent evaluation of internal control over financial reporting, to the
registrant’s auditors and the audit committee of the registrant’s board of directors (or persons performing the equivalent functions):

a)

b)

Dated: February 24, 2023

All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are
reasonably likely to adversely affect the registrant’s ability to record, process, summarize and report financial information; and

Any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant’s
internal control over financial reporting.

/s/ BRYAN A. SHINN
Name: Bryan A. Shinn
Title: Chief Executive Officer

 
 
 
 
 
 
 
 
Exhibit 31.2

I, Donald A. Merril, certify that:

CERTIFICATION

1.

2.

3.

4.

I have reviewed this annual report on Form 10-K of U.S. Silica Holdings, Inc. (the “Company”) for the year ended December 31, 2022;

Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the
statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this
report;

Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects the
financial condition, results of operations and cash flows of the registrant as of, and for, the periods presented in this report;

The registrant’s other certifying officer and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in
Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal control over financial reporting (as defined in Exchange Act Rules 13a-15(f) and 15d-
15(f)) for the registrant and have:

a)

b)

c)

d)

Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our
supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to
us by others within those entities, particularly during the period in which this report is being prepared;

Designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under
our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial
statements for external purposes in accordance with generally accepted accounting principles;

Evaluated the effectiveness of the registrant’s disclosure controls and procedures and presented in this report our conclusions about
the effectiveness of the disclosure controls and procedures, as of the end of the period covered by this report based on such
evaluation; and

Disclosed in this report any change in the registrant’s internal control over financial reporting that occurred during the registrant’s
most recent fiscal quarter (the registrant’s fourth fiscal quarter in the case of an annual report) that has materially affected, or is
reasonably likely to materially affect, the registrant’s internal control over financial reporting; and

5.

The registrant’s other certifying officer and I have disclosed, based on our most recent evaluation of internal control over financial reporting, to the
registrant’s auditors and the audit committee of the registrant’s board of directors (or persons performing the equivalent functions):

a)

b)

All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are
reasonably likely to adversely affect the registrant’s ability to record, process, summarize and report financial information; and

Any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant’s
internal control over financial reporting.

Dated: February 24, 2023

/s/ DONALD A. MERRIL
Name: Donald A. Merril
Title: Chief Financial Officer

 
 
 
 
 
 
 
 
SECTION 1350 CERTIFICATION

Exhibit 32.1

I, Bryan A. Shinn, Chief Executive Officer, U.S. Silica Holdings, Inc. (the “Company”), hereby certify, on the date hereof, pursuant to 18 U.S.C. Section 1350,
as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that to the best of my knowledge:

i.

ii.

The Annual Report on Form 10-K of the Company for the year ended December 31, 2022 (the “Report”) fully complies with the
requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934, as amended; and

The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the
Company.

Dated: February 24, 2023

A signed copy of this original statement required by Section 906 has been provided to the Company and will be retained by the Company and furnished to the
Securities and Exchange Commission or its staff on request.

/s/ BRYAN A. SHINN
Name: Bryan A. Shinn
Title: Chief Executive Officer

 
 
 
 
 
SECTION 1350 CERTIFICATION

Exhibit 32.2

I, Donald A. Merril, Chief Financial Officer, U.S. Silica Holdings, Inc. (the “Company”), hereby certify, on the date hereof, pursuant to 18 U.S.C. Section 1350,
as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that to the best of my knowledge:

i.

ii.

The Annual Report on Form 10-K of the Company for the year ended December 31, 2022 (the “Report”) fully complies with the
requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934, as amended; and

The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the
Company.

Dated: February 24, 2023

A signed copy of this original statement required by Section 906 has been provided to the Company and will be retained by the Company and furnished to the
Securities and Exchange Commission or its staff on request.

/s/ DONALD A. MERRIL
Name: Donald A. Merril
Title: Chief Financial Officer

 
 
 
 
 
Exhibit 95.1

Mine Safety Disclosure

The  following  disclosures  are  provided  pursuant  to  the  Dodd-Frank  Wall  Street  Reform  and  Consumer  Protection  Act  (the  “Act”)  and  Item  104  of
Regulation S-K, which requires certain disclosures by companies required to file periodic reports under the Securities Exchange Act of 1934, as amended, that
operate mines regulated under the Federal Mine Safety and Health Act of 1977 (the “Mine Act”).

Mine Safety Information. Whenever the Federal Mine Safety and Health Administration (“MSHA”) believes a violation of the Mine Act, any health or
safety  standard  or  any  regulation  has  occurred,  it  may  issue  a  citation  which  describes  the  alleged  violation  and  fixes  a  time  within  which  the  U.S.  mining
operator must abate the alleged violation. In some situations, such as when MSHA believes that conditions pose a hazard to miners, MSHA may issue an order
removing miners from the area of the mine affected by the condition until the alleged hazards are corrected. When MSHA issues a citation or order, it generally
proposes a civil penalty, or fine, as a result of the alleged violation, that the operator is ordered to pay. Citations and orders can be contested and appealed, and
as part of that process, are often reduced in severity and amount, and are sometimes dismissed. The number of citations, orders and proposed assessments vary
depending  on  the  size  and  type  (underground  or  surface)  of  the  mine  as  well  as  by  the  MSHA  District’s  approach  to  enforcement.  Due  to  timing  and  other
factors, the data below may not agree with the mine data retrieval system maintained by the MSHA at www.MSHA.gov

The following table details the citations and orders issued and civil penalties assessed to us by MSHA during the quarter ended December 31, 2022:

Mine or Operating
Name/MSHA
Identification Number

Section 104
S&S
Citations

Section
104(b)
Orders

Section
104(d)
Citations
and Orders

Section
110(b)(2)
Violations

Section
107(a)
Orders

Total Dollar
Value of MSHA
Assessments
Proposed (1)

Total Number
of Mining
Related
Fatalities

Received
Notice of
Pattern of
Violations
Under Section
104(e) (yes/no)

Received Notice
of Potential to
Have Pattern
Under Section
104(e) (yes/no)

Legal
Actions
Pending as
of Last Day
of Period

Legal
Actions
Initiated
During
Period

Legal
Actions
Resolved
During
Period

(whole dollars)

Berkley Springs, WV /
4602805

Celatom Mine, OR /
3503237

Celatom Plant, OR /
3503236

Cheto Mine, AZ /
0200103

Clark, NV / 2600677

Columbia, SC / 3800138

Crane, TX / 4105331

Dubberly, LA / 1600489

Fernley, NV / 2601950

Festus, MO / 2302377

Fowlkes Mine, MS /
2200460

Hazen Mine, NV/
2600679

Hurtsboro, AL / 100617

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

$0.00

$0.00

$532.00

$0.00

$0.00

$716.00

$0.00

$0.00

$0.00

$266.00

$0.00

$0.00

$0.00*

0

0

0

0

0

0

0

0

0

0

0

0

0

No

No

No

No

No

No

No

No

No

No

No

No

No

No

No

No

No

No

No

No

No

No

No

No

No

No

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

Jackson, MS / 2200415

Jackson, TN / 4002937

Kosse, TX / 4100262

Lamesa, TX / 4105363

Lovelock (Colado Plant) /
2600680

Lovelock, NV (Colado
Mine) / 2600672

Mapleton, PA / 3603122

Mauricetown, NJ /
2800526

Middletown, TN /
4002968

Mill Creek Mine, OK /
3400836

Mill Creek Plant, OK /
3400377

Millen, GA / 0901232

Montpelier, VA / 4402829

Ottawa, IL / 1101013

Pacific, MO / 2300544

Popcorn Mine, NV /
2602236

Port Elizabeth, NJ /
2800510

Rockwood, MI / 2000608

Sparta, WI / 4703644

Tyler, TX /4104182

Utica, IL / 1103268

0

0

0

0

0

0

1

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

$0.00*

$0.00

$0.00

$0.00

$0.00

$0.00

$0.00*

$133.00

$0.00

$0.00

$0.00

$0.00

$0.00

$0.00

$0.00

$0.00

$0.00

$0.00*

$0.00

$0.00

$0.00

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

No

No

No

No

No

No

No

No

No

No

No

No

No

No

No

No

No

No

No

No

No

No

No

No

No

No

No

No

No

No

No

No

No

No

No

No

No

No

No

No

No

No

0

0

0

0

27

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

(1)

Amounts  included  are  the  total  dollar  value  of  proposed  assessments  received  from  MSHA  from  October  1,  2022  through  December  31,  2022,
regardless of whether the assessment has been challenged or appealed. Citations and orders can be contested and appealed, and as part of that process,
are  sometimes  reduced  in  severity  and  amount,  and  sometimes  dismissed.  The  number  of  citations,  orders,  and  proposed  assessments  vary  by  the
MSHA District’s approach to enforcement and vary depending on the size and type of the operation

* As of December 31, 2022, MSHA had not yet proposed an assessment for 3 non-S&S citations at the Hurtsboro Plant, AL.
* As of December 31, 2022, MSHA had not yet proposed an assessment for 3 non-S&S citations at the Jackson Plant, MS.
* As of December 31, 2022, MSHA had not yet proposed an assessment for 4 non-S&S citations and one S&S citation at the Mapleton Plant, PA.
* As of December 31, 2022, MSHA had not yet proposed an assessment for 4 non-S&S citations and one S&S citation at the Rockwood Plant, MI.

TECHNICAL REPORT SUMMARY

SILICA SAND RESOURCES AND RESERVES

OTTAWA OPERATION

LaSalle County, Illinois

Prepared For

U.S. SILICA COMPANY

Katy, Texas

By

John T. Boyd Company

Mining and Geological Consultants

Pittsburgh, Pennsylvania

Report No. 3076.019

FEBRUARY 2023

JOHN T. BOYD COMPANY

 JOHN T. BOYD COMPANY

    Mining and Geological Consultants

February 16, 2023

JOHN T. BOYD COMPANY

 JOHN T. BOYD COMPANY

    Mining and Geological Consultants

File: 3076.019

U.S. Silica Company
24275 Katy Freeway, Suite 600
Katy, TX 77494-7271

Attention:    Mr. Terry Lackey

    Mining Director

Subject:    Technical Report Summary
        Silica Sand Resources and Reserves
        Ottawa Operation
        LaSalle County, Illinois

Ladies and Gentlemen:

The John T. Boyd Company (BOYD) was retained by U.S. Silica Company (U.S. Silica) to complete an independent technical
assessment of the silica sand resource and reserve estimates for the Ottawa Operation as of December 31, 2022.

This technical report summary: (1) summarizes material technical and geoscientific information for the subject mining property, (2)
provides the conclusions of our technical assessment, and (3) provides a statement of silica sand resources and reserves for the
Ottawa Operation.

Respectfully submitted,

JOHN T. BOYD COMPANY
By:

John T. Boyd II
President and CEO

q:\eng_wp\3076.019 u.s. silica - ottawa\wp\report\cover letter.docxc

JOHN T. BOYD COMPANY

    TABLE OF CONTENTS

    Page
LETTER OF TRANSMITTAL

TABLE OF CONTENTS

GLOSSARY AND ABBREVIATIONS

1.0    EXECUTIVE SUMMARY     1-1
    1.1    Introduction     1-1
    1.2    Property Description     1-1
    1.3    Geology     1-3
    1.4    Exploration     1-3
    1.5    Silica Sand Resources and Reserves     1-4
    1.6    Operations     1-5
        1.6.1    Mining     1-5
        1.6.2    Processing     1-6
        1.6.3    Other Infrastructure     1-6
    1.7    Financial Analysis     1-7
        1.7.1    Market Analysis     1-7
        1.7.2    Capital and Operating Cost Estimates     1-7
        1.7.3    Economic Analysis     1-8
    1.8    Permitting Requirements     1-10
    1.9    Conclusions     1-10

2.0    INTRODUCTION     2-1
    2.1    Registrant     2-1
    2.2    Terms of Reference and Purpose     2-1
    2.3    Expert Qualifications     2-2
    2.4    Principal Sources of Information     2-3
    2.5    Personal Inspections     2-3
    2.6    Report Version     2-4
    2.7    Units of Measure     2-4

3.0    PROPERTY DESCRIPTION     3-1
    3.1    Location     3-1
    3.2    Property Rights    3-1    
    3.3    Encumbrances    3-3
        3.3.1 Fees and Royalties    3-3
        3.3.2 Permitting Requirements    3-3
        3.3.3 Mining Restrictions    3-3
        3.3.4 Other Significant Factors or Risks    3-4

4.0    PHYSIOGRAPHY, ACCESSIBILITY, AND INFRASTRUCTURE     4-1
    4.1    Topography, Elevation, and Vegetation     4-1
    4.2    Accessibility     4-1
    4.3    Climate    4-2
    4.4    Infrastructure Availability and Sources     4-2

JOHN T. BOYD COMPANY

        
    
    TABLE OF CONTENTS    - Continued  

    Page

5.0    HISTORY     5-1
    5.1    Reserve Acquisition     5-1
    5.2    Exploration and Development     5-1

6.0    GEOLOGICAL SETTING, MINERALIZATION, AND DEPOSIT     6-1
    6.1    Regional Geology     6-1
    6.2    Local Geology     6-2
        6.2.1    Stratigraphy     6-2
        6.2.2    Structural Geology     6-3
    6.3    Property Geology     6-4

7.0    EXPLORATION DATA     7-1
    7.1    Background     7-1
    7.2    Exploration Procedures     7-1
        7.2.1    Drilling     7-1
        7.2.2    Sand Quality Sampling     7-2
        7.2.3    Sand Testing     7-2
        7.2.4    Other Exploration Methods     7-3
    7.3    Exploration Results     7-4
        7.3.1    Summary of Exploration     7-4
        7.3.2    Silica Sand Quality    7-6
        7.3.3    Grain Size Distribution    7-6
        7.3.4    Grain Shape (Sphericity and Roundness)    7-7
        7.3.5    Crush Resistance    7-7
        7.3.6    Mineralogical Analyses    7-7
    7.4    Data Verification     7-8
    7.5    Adequacy of Exploration and Sampling    7-8

8.0    SAMPLE PREPARATION, ANALYSIS, AND SECURITY     8-1

9.0    DATA VERIFICATION     9-1

10.0    MINERAL PROCESSING AND METALLURGICAL TESTING     10-1

JOHN T. BOYD COMPANY

    
    
    
    TABLE OF CONTENTS    - Continued  

    Page

11.0    SILICA SAND RESOURCE ESTIMATE     11-1
    11.1    Applicable Standards and Definitions     11-1
    11.2    Silica Sand Resources     11-2
        11.2.1     Methodology     11-2
        11.2.2     Estimation Criteria     11-2
        11.2.3     Classification     11-4
        11.2.4     Silica Sand Resource Estimate     11-5
        11.2.5     Validation     11-5

12.0    SILICA SAND RESERVE ESTIMATE     12-1
    12.1    Applicable Standards and Definitions     12-1
    12.2    Silica Sand Reserves     12-2
        12.2.1     Methodology    12-2
        12.2.2     Classification    12-3
        12.2.3     Silica Sand Reserve Estimate     12-5
        12.2.4     Reconciliation with Previous Estimates     12-6

13.0    MINING METHODS     13-1
    13.1    Mining Operation    13-1
    13.2    Mine Equipment and Staffing     13-3
        13.2.1     Mine Equipment     13-3
        13.2.2     Staffing     13-3
    13.3    Engineering and Planning     13-4
    13.4    Mining Sequence and Production     13-4

14.0    PROCESSING OPERATIONS     14-1
    14.1    Overview     14-1
        14.1.1 Wet Processing Plant    14-1
        14.1.2 Sizing and Fine Sand Plant    14-3
        14.1.3 Grinding Mills    14-3
        14.1.4 ASTM Circuit    14-3
    14.2    Production     14-4
    14.3    Conclusion     14-4

15.0    MINE INFRASTRUCTURE     15-1
    15.1    Overview     15-1
    15.2    Transportation     15-1
    15.3    Utilities    15-2
    15.4    Tailings Disposal    15-2
    15.5    Other Structures    15-3

16.0    MARKET STUDIES     16-1
    16.1    Product Specifications     16-1
    16.2    Historical Sales     16-1
    16.3    Market Outlook     16-2

17.0    PERMITTING AND COMPLIANCE     17-1
    17.1    Permitting     17-1
    17.2    Compliance     17-3
    17.3    Post-Mining Land Use and Reclamation     17-3
    17.4    Community Engagement     17-4

JOHN T. BOYD COMPANY

    TABLE OF CONTENTS    - Continued  

    Page

18.0    CAPITAL AND OPERATING COSTS     18-1
    18.1    Historical Financial Performance     18-1
    18.2    Estimated Costs     18-2
        18.2.1 Projected Capital Expenditures     18-2
        18.2.2 Projected Operating Costs    18-3

19.0    ECONOMIC ANALYSIS     19-1
    19.1    Approach     19-1
    19.2    Assumptions and Limitations     19-2
    19.3    Financial Model Results    19-2
    19.4    Sensitivity Analysis    19-5

20.0    ADJACENT PROPERTIES     20-1

21.0    OTHER RELEVANT DATA AND INFORMATION     21-1

22.0    INTERPRETATION AND CONCLUSIONS     22-1
    22.1    Audit Findings     22-1
    22.2    Significant Risks and Uncertainties     22-1

23.0    RECOMMENDATIONS     23-1

24.0    REFERENCES     24-1

25.0    RELIANCE ON INFORMATION PROVIDED BY REGISTRANT     25-1

JOHN T. BOYD COMPANY

    
    TABLE OF CONTENTS    - Continued  

    Page

List of Tables
1.1    Ottawa Operation Silica Sand Resources (as of December 31, 2022)     1-4
1.2    Ottawa Operation Silica Sand Reserves (as of December 31, 2022)    1-5
1.3    Financial Results    1-9
1.4    DCF-NPV Analysis    1-9
3.1    Property Ownership     3-1
7.1    Descriptive Statistics, Stratigraphic Interval Thickness    7-4
7.2    Weighted Average Particle Size Distribution    7-6
11.1    Silica Sand Resource Classification Criteria    11-4
11.2    Ottawa Operation Silica Sand Resources (as of December 31, 2022)    11-5
12.1    Ottawa Operation Silica Sand Reserves (as of December 31, 2022)    12-5
13.1    Employees by Classification    13-3
16.1    Historical Sales Data     16-1
18.1    Historical Financials    18-1
18.2    Projected Capital Costs    18-2
19.1    Annual Production and Cash Flow Forecast Ottawa Operation     19-3
19.2    Financial Results    19-4
19.3    DCF-NPV Analysis     19-4
19.4    After-Tax NPV  Sensitivity Analysis ($ millions)     19-5
25.1    Information Relied Upon from Registrant    25-1

12.5

JOHN T. BOYD COMPANY

    TABLE OF CONTENTS    - Continued  

    Page

List of Figures
1.1    General Location Map     1-2
3.1    Map Showing Site Layout Ottawa Operation     3-2
6.1    Generalized Stratigraphic Chart, Ottawa, Illinois    6-2
6.2    Map Showing Silica Sand Thickness Isopaches Ottawa Operation    6-5
6.3    Cross-Section A – A’ Ottawa Operation    6-6
7.1    Map Showing Drill Hole Locations Ottawa Operation    7-5
12.1    Relationship Between Mineral Resources and Mineral Reserves    12-2
12.2    Map Showing Mineral Reserve Classification Ottawa Operation    12-4
13.1    Loading Operations at the Ottawa Operation    13-2
13.2    Recent Historical and LOM Forecasted Mining Production    13-5
13.3    Map Showing Life-of-Mine Plan Ottawa Operation    13-6
14.1    Simplified Flow Sheet Ottawa Operation    14-2
14.2    Recent Historical and LOM Forecasted Processing Plant Production    14-4

q:\eng_wp\3076.019 u.s. silica - ottawa\wp\report\toc.doc

JOHN T. BOYD COMPANY

1

000

$

%

AMSL

API

ARO

ASP

ASTM

BNSF

BOYD

CapEx

Constant Dollar

CSX

DCF

Discount Rate

EBIT

EBITDA

Frac Sand

ft

HDPE

IDNR

:

:

:

:

:

:

:

:

:

:

:

:

:

:

:

:

:

:

:

:

:

GLOSSARY OF ABBREVIATIONS AND DEFINITIONS

Thousand(s)

US dollar(s)

Percent or percentage

Above mean sea level

American Petroleum Institute

Asset Retirement Obligations

Average Selling Price

ASTM International (formerly American Society for Testing and Materials)

BNSF Railway Company

John T. Boyd Company

Capital expenditures

A monetary measure that is not influenced by inflation and used to compare time periods.
Sometimes referred to as “real dollars”.

CSX Transportation

Discounted Cash Flow

A rate of return used to discount future cash flows based on the return investors expect to
receive from their investment.

Earnings before interest and taxes

Earnings before interest, taxes, depreciation, and amortization

See “Proppant Sand”

Foot/feet

High-density polyethylene

Illinois Department of Natural Resources

JOHN T. BOYD COMPANY

    GLOSSARY OF ABBREVIATIONS AND DEFINITIONS - Continued 

2

Indicated Silica Sand
Resource

IEMA

ILEPA

Inferred Silica Sand
Resource

IRR

ISO

ISP

lb

LOM

Measured Silica Sand
Resource

Mesh

Mineral Reserve

:

:

:

:

:

:

:

:

:

:

:

That part of a silica sand resource for which quantity and quality are estimated based on
adequate geological evidence and sampling. The level of geological certainty associated with
an indicated silica sand resource is sufficient to allow a qualified person to apply modifying
factors in sufficient detail to support mine planning and evaluation of the economic viability of
the deposit. Because an indicated silica sand resource has a lower level of confidence than the
level of confidence of a measured silica sand resource, an indicated silica sand resource may
only be converted to a probable silica sand reserve.

Illinois Emergency Management Agency

Illinois Environmental Protection Agency

That part of a silica sand resource for which quantity and quality are estimated based on limited
geological evidence and sampling. The level of geological uncertainty associated with an
inferred silica sand resource is too high to apply relevant technical and economic factors likely
to influence the prospects of economic extraction in a manner useful for evaluation of economic
viability. Because an inferred silica sand resource has the lowest level of geological confidence
of all silica sand resources, which prevents the application of the modifying factors in a manner
useful for evaluation of economic viability, an inferred silica sand resource may not be
considered when assessing the economic viability of a mining project, and may not be
converted to a silica sand reserve.

Internal rate-of-return

International Organization for Standardization

Industrial and Specialty Products

Pound

Life-of-Mine

That part of a silica sand resource for which quantity and quality are estimated based on
conclusive geological evidence and sampling. The level of geological certainty associated with
a measured silica sand resource is sufficient to allow a qualified person to apply modifying
factors, as defined herein, in sufficient detail to support detailed mine planning and final
evaluation of the economic viability of the deposit. Because a measured silica sand resource
has a higher level of confidence than the level of confidence of either an indicated silica sand
resource or an inferred silica sand resource, a measured silica sand resource may be
converted to a proven silica sand reserve or to a probable silica sand reserve

A measurement of particle size often used in determining the size distribution of granular
material.

See “Silica Sand Reserve”

JOHN T. BOYD COMPANY

    
    GLOSSARY OF ABBREVIATIONS AND DEFINITIONS - Continued 

3

Mineral Resource

Modifying Factors

MSHA
NPV

O&G

Probable Silica Sand
Reserve

Production Stage Property

Proppant Sand

Proven Silica Sand
Reserve

PSI

QP

:

See “Silica Sand Resource”

The factors that a qualified person must apply to indicated and measured silica sand resources
and then evaluate to establish the economic viability of silica sand reserves. A qualified person
must apply and evaluate modifying factors to convert measured and indicated silica sand
resources to proven and probable silica sand reserves. These factors include but are not
restricted to: mining; processing; infrastructure; economic; marketing; legal; environmental
compliance; plans, negotiations, or agreements with local individuals or groups; and
governmental factors. The number, type and specific characteristics of the modifying factors
applied will necessarily be a function of and depend upon the mineral, mine, property, or
project.

: Mine Safety and Health Administration. A division of the U.S. Department of Labor
:

Net Present Value

:

:

:

:

:

:

:

Oil and Gas

The economically mineable part of an indicated and, in some cases, a measured silica sand
resource.

A property with material extraction of silica sand reserves.

Proppant (frac) sand is a naturally occurring, high silica content quartz sand, with grains that
are generally well rounded and exhibit high compressive strength characteristics relative to
other proppant sand. It is utilized as a prop or “proppant” in unconventional shale frac well
completions.

The economically mineable part of a measured silica sand resource which can only result from
conversion of a measured silica sand resource.

Pounds per square inch

Qualified Person

JOHN T. BOYD COMPANY

    
    GLOSSARY OF ABBREVIATIONS AND DEFINITIONS - Continued 

4

Qualified Person

:

An individual who is:

1. A mineral industry professional with at least five years of relevant experience in the type of
mineralization and type of deposit under consideration and in the specific type of activity
that person is undertaking on behalf of the registrant; and

2. An eligible member or licensee in good standing of a recognized professional organization

at the time the technical report is prepared. For an organization to be a recognized
professional organization, it must:

a. Be either:

i. An organization recognized within the mining industry as a reputable professional

association; or

ii.A board authorized by U.S. federal, state, or foreign statute to regulate

professionals in the mining, geoscience, or related field;

b. Admit eligible members primarily based on their academic qualifications and

experience;

c. Establish and require compliance with professional standards of competence and

ethics;

d. Require or encourage continuing professional development;
e. Have and apply disciplinary powers, including the power to suspend or expel a

member regardless of where the member practices or resides; and

f. Provide a public list of members in good standing.

Run-of-Mine. The processing feed material, including silica sand and any inseparable waste,
excavated from the mine.

U.S. Securities and Exchange Commission

Silica sand reserve is an estimate of tonnage and grade or quality of indicated and measured
silica sand resources that, in the opinion of the qualified person, can be the basis of an
economically viable project. More specifically, it is the economically mineable part of a
measured or indicated silica sand resource, which includes diluting materials and allowances
for losses that may occur when the material is mined or extracted.

JOHN T. BOYD COMPANY

ROM

SEC

Silica Sand Reserve

:

:

:

    
 
 
    GLOSSARY OF ABBREVIATIONS AND DEFINITIONS - Continued 

5

Silica Sand Resources

S-K 1300

SPCC

Ton

U.S. Silica

:

:

:

:

:

Silica sand resource is a concentration or occurrence of material of economic interest in or on
the Earth's crust in such form, grade or quality, and quantity that there are reasonable
prospects for economic extraction. A silica sand resource is a reasonable estimate of
mineralization, taking into account relevant factors such as cut-off grade, likely mining
dimensions, location or continuity, that, with the assumed and justifiable technical and
economic conditions, is likely to, in whole or in part, become economically extractable. It is not
merely an inventory of all mineralization drilled or sampled.

Subpart 1300 and Item 601(b)(96) of the U.S. Securities and Exchange Commission’s
Regulation S-K

Spill Prevention, Controls and Countermeasure

Short Ton. A unit of weight equal to 2,000 pounds

U.S. Silica Company, its parent company (U.S. Silica Holdings, Inc.) and its consolidated
subsidiaries as a combined entity.

Q:\ENG_WP\3076.019 U.S. Silica - Ottawa\Ottawa Working Draft\Glossary.docx

JOHN T. BOYD COMPANY

    
1-1

1.0    EXECUTIVE SUMMARY

1.1    Introduction

U.S. Silica’s Ottawa Operation is an active surface silica sand mining and processing operation that has been in existence for over

100 years.

BOYD prepared this technical report summary for U.S. Silica in support of their disclosure of silica sand reserves for the Ottawa

Operation in accordance with Subpart 1300 and Item 601(b)(96) of the SEC's Regulation S-K (S-K 1300). The purpose of this report

is threefold: (1) to summarize material technical and geoscientific information for the subject mining property, (2) to provide the

conclusions of our technical assessment, and (3) to provide a statement of silica sand resources and/or reserves for the Ottawa

Operation.

Information used in our assessment was obtained from: (1) files provided by U.S. Silica, (2) discussions with U.S. Silica personnel,

(3) records on file with regulatory agencies, (4) public sources, and (5) nonconfidential information in BOYD’s possession.

Unless otherwise noted, the effective date of the information, including estimates of silica sand reserves, is December 31, 2022.

Weights and measurements are expressed in the US customary measurement system throughout this report.

1.2    Property Description

U.S. Silica’s Ottawa Operation is a surface silica sand mining and processing operation located immediately west of the City of

Ottawa in LaSalle County, Illinois. The cities of Chicago and Peoria, Illinois, are located approximately 95 miles east-northeast and

75 miles southwest, respectively, of the Ottawa Operation. The general location of the Ottawa Operation is provided in Figure 1.1,

following this page.

The property is bisected by the Illinois River into the North Ottawa and South Ottawa sites. The mine offices, maintenance facilities,
processing plant, loadout facilities, and former mining pits are located on the North Ottawa site, while the active (South Ottawa Pit)

and future mining areas (West Ottawa and Mississippi Sand Pit) are located on the South Ottawa site. A slurry line driven under the
Illinois River connects the two sites, and

JOHN T. BOYD COMPANY

1-2

1-3

is used to transport Run-of-Mine (ROM) sand material from South Ottawa to the processing plant.

The Ottawa Operation has mined silica sand exclusively from the St. Peter Sandstone Formation for over 100 years. Within the
boundaries of the Ottawa Operation, U.S. Silica wholly owns both surface and mineral rights on all ±2,072 acres. BOYD is not

aware of any encumbrances, litigation, or orders which would hinder continued development of the property.

1.3    Geology
The Ottawa Operation’s target silica bearing formation is the St. Peter Sandstone, which is a massive formation in areal extent and
thickness. Aerially, it extends from Minnesota to Arkansas and from Illinois into Nebraska and South Dakota. On a regional basis,

the St. Peter Sandstone ranges in thickness from a few feet to over 1,200 ft, with a general thickness of 100 ft to 200 ft. In northern
Illinois, the thickness can be over 300 ft thick.

At the Ottawa Operation, the St. Peter Sandstone is flat lying with no evidence of faulting, and has been eroded to an average

thickness of approximately 90 ft. The formation is a white to buff colored, fine- to medium-grained ortho-quartzite. It contains
rounded, clear polished sand quartz grains with minor secondary silica and clay cement.

Grain size distribution and iron-staining drives the mine planning. Iron tends to be concentrated near the surface and is visible in
orange staining. Iron also increases at the bottom sandstone contact, occurring mostly as pyrite. The deposit is coarser in its top

half. Where the upper part of the formation is eroded, multiple mining faces must operate to ensure adequate sand is available to
meet product specifications.

In the defined resource areas, the St. Peter Sandstone is overlain by a thin layer of overburden material consisting of clay, sandy
gravel, peat, and limestone cap rock.

1.4    Exploration
The St. Peter Sandstone has been extensively explored and mined on the Ottawa Operation. The North Ottawa site was mined out
by 2010, and exploration on the South Ottawa site began in the year 2000. U.S. Silica provided data for 225 drill holes, wells, field
measurements, and test holes in and around the South Ottawa site. These data were utilized to define the lateral extent, thickness,

particle size distribution, and mineralogy of the remaining St. Peter Sandstone reserves at the Ottawa Operation.

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BOYD’s audit indicates that in general: (1) U.S. Silica has performed extensive drilling and sampling work on the subject property,
(2) the work completed has been done by competent personnel, and (3) the amount of data available combined with extensive knowledge
and historic production of the St. Peter Sandstone, are sufficient to confirm the thickness, lateral extents, and quality characteristics of the South
Ottawa silica sand reserves.

1.5    Silica Sand Resources and Reserves
As shown in Table 1.1, below, U.S. Silica owns approximately 88,000 in place tons of inferred silica sand resources, exclusive of

silica sand reserves, at the Ottawa Operation, as of December 31, 2022.

While these “additional” silica sand resources have not been included in the Ottawa Operation’s life-of-mine (LOM) plan, they are
considered to have prospects for eventual economic extraction by virtue of their similarity—in terms of demonstrated extraction
methods and expected finished product qualities—to those converted to silica sand reserves.

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U.S. Silica’s estimated surface mineable silica sand reserves for the Ottawa Operation total 78.9 million saleable product tons
remaining as of December 31, 2022. The silica sand reserves are fully owned by U.S. Silica and are summarized in Table 1.2,

below.

The Ottawa Operation has a well-established history of mining, processing, and selling silica sand products into various markets.

BOYD has concluded that sufficient studies have been undertaken to enable the silica sand resources to be converted to silica sand

reserves based on proposed operating methods and forecasted costs and revenues.

1.6    Operations

1.6.1    Mining

Current mining at the Ottawa Operation takes place on the South Ottawa site, where the St. Peter Sandstone is excavated using

conventional surface mining methods. The thin overlying layer of unconsolidated overburden is scraped off and stockpiled in order

to expose the St. Peter Sandstone Formation. The mineable sandstone interval is then drilled and blasted in benches ranging from

40 to 75 ft high. An excavator or front-end loader is then used to load the shot and blasted sandstone into articulated haul trucks.

The haul trucks deliver raw sand material to a monitor station, where the material is further broken down via high-pressure water

jets, that also create a sand slurry. The sand slurry is then pumped through lines that run under the Illinois River to the processing

facilities which are located on the North Ottawa site, where processing of the ROM silica sand begins.

Over the past seven years, the operation has mined over 24 million tons of raw sand. During late 2019 and 2020, production fell to

match decreased customer demand due to the COVID-19 pandemic from approximately 4 million tons per year to under 2.5 million

tons. U.S. Silica’s Life-of-Mine (LOM) plan forecasts mining 91.2 million tons of ROM silica sand at a nominal rate of 3.8 million tons

per year for the remaining life of the operation.

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BOYD reviewed the LOM plans for U.S. Silica’s Ottawa Operation to determine whether the plans: (1) utilize generally accepted

engineering practices, and (2) align with historical and industry norms. Based on our assessment, it is BOYD’s opinion that the

forecasted production levels for the Ottawa Operation are reasonable, logical, and consistent with typical sandstone surface mining

practices in the St. Peter Sandstone and historical results achieved by U.S. Silica.

1.6.2    Processing

The Ottawa Operation’s wet and dry processing plants, along with grinding mills, are located on the north shore of the Illinois River,

on the Ottawa North site. The processing facilities also include an ASTM circuit, which is used to produce ASTM 20/30 and ASTM

C109 compliant sand for cement and abrasion testing. The Ottawa Operation is the world’s only supplier of fully ASTM-compliant

sands.

Pumped ROM slurry material from the South Ottawa site arrives at the processing plant, where it is washed to remove fine waste

(clay and silt) material, sorted and sized, then dried. At this point, the silica sand is divided into two streams depending on finished

product requirements—whole grain sand is sorted and sized again prior to packaging, while ground silica products are milled to

produce fine silica powders.

Over its history, the processing plant has been upgraded and expanded several times as needed to meet specific market demands.

The plants currently run 24 hours a day, 365 days a year, with a nominal capacity of 3.29 million tons of finished sand per year.

Based on our review, it is BOYD’s opinion that the processing methods and existing equipment at the plant will be sufficient for the

forecasted production levels over the life of the operation.

1.6.3    Other Infrastructure

The Ottawa Operation is supported by various utilities and transportation networks needed to allow processing and transportation of

finished silica sands.

Electricity to the North Ottawa site is delivered through an above-ground network that terminates at a substation on the west end of

the processing facility, and from there electricity is distributed via several underground and above-ground powerlines.

Initial makeup water is obtained through a series of wells drilled on the South Ottawa site, and recovered and recycled for reuse

whenever possible. Potable water is delivered through the City of Ottawa’s public water system.

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Natural gas is supplied via several underground pipelines.

Tailings from processing consist generally of clays, silts, and very fine sands, which are typically disposed of in old mining pit

impoundments. The tailings ponds are currently located east of the processing plant, and are designed to accommodate rejects

produced during the next five to ten years of production. At that time, it is expected that mining in the South Ottawa site will have

advanced to the West Ottawa Pit, and the mined out South Ottawa Pit will be used for tailings.

Infrastructure to transport finished sand product include three different systems currently in-place at the Ottawa Operation: (1) the

Illinois Railway, a former BNSF short line, transports rail cars to and from a CSX interchange located in the City of Ottawa; access

from there is then available to several Class 1 railroads – BNSF, Union Pacific, and Norfolk Southern; (2) numerous local, county,

and state roadways and highways that are within four miles of the processing facilities; and (3) U.S. Silica also maintains access to

several third-party owned barge terminals, which are located on the north shore of the Illinois River, and are all situated on land

owned by U.S. Silica.

1.7    Financial Analysis

1.7.1    Market Analysis

The Ottawa Operation is U.S. Silica’s largest “blended” operation, supplying various grades of silica sand to both the Oil and Gas

(O&G) and the Industrial and Specialty Products (ISP) markets. Their finished silica sand products are used in variety of industrial

applications by a large customer base.

U.S. Silica’s product sales were materially impacted by the COVID-19 pandemic, with sales dropping precipitously in 2019 due to

decreased customer demand. However, their sales volumes and revenues have recovered substantially, and continued growth is

expected over the long-term.

1.7.2    Capital and Operating Cost Estimates

The Ottawa Operation’s financial performance over the last years is summarized as follows:

• Average realization (selling price) for finished silica sand products increased from $36.91 per ton sold in 2020 to $42.37 per ton

sold in 2022.

•

Total cash cost of sales also increased from $29.48 per ton sold in 2020 to $32.85 per ton sold in 2022.

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• EBITDA margin increased slightly from 20.1% in 2020 to 22.5% in 2022.

• Capital expenditures totaled almost $9.5 million over the last three years, averaging $1.27 per ton sold.

Forward-looking production and unit cost estimates are based on actual past performance and subject to U.S. Silica’s customary

internal budget review and approvals process. In BOYD’s opinion, operating volumes are well-defined and understood, as are

mining and processing productivities.

The Ottawa Operation and related facilities are fully developed and should require no near-term major capital investment to

maintain full commercial production. Historically, the timing and amount of capital expenditures has been largely discretionary and

within U.S. Silica’s control. Their budgetary allocations for sustaining and discretionary capital expenditures over the next three

years totals $8.3 million. Thereafter, capital expenditures are expected to rise 3% year-over-year from 2025’s $2.2 million. BOYD

considers the near-term detailed capital expenditure schedule as presented by U.S. Silica to be reasonable and representative of

the capital necessary to operate the Ottawa Operation.

Operating cost estimates were developed based on recent actual costs and considering specific operational activity levels and cost

drivers. In the near-term, U.S. Silica expects their unit operating costs to stay relatively level (on an uninflated basis). As such, the

projected total cash cost of sales over the life of the mine is $32.85 per ton sold. As the operation is in a steady state, BOYD

considers the future operating cost estimates to be reasonable and appropriate.

1.7.3    Economic Analysis

An economic analysis of the Ottawa Operation was prepared in-house by U.S. Silica as part of their annual budgeting process. The

financial model forecasts future free cash flow from silica sand production and sales over the life cycle of the Ottawa Operation

using the annual forecasts of production, sales revenues, and operating and capital costs.

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Table 1.3, below, provides a summary of the estimated financial results for remaining life of the Ottawa Operation.

1-9

Table 1.4 summarizes the results of the pre-tax and after-tax discounted cash flows (DCF) and net present value (NPV) analyses for
the Ottawa Operation.

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The NPV estimate was made for purposes of confirming the economic viability of the reported silica sand reserves and not for

purposes of valuing the U.S. Silica, Ottawa Operation, or its assets. Internal rate-of-return (IRR) and project payback were not

calculated, as there was no initial investment considered in the financial analysis.

BOYD reviewed the financial model and its inputs in detail, and opined that the model provides a reasonable and accurate reflection

of the Ottawa Operation’s expected economic performance based on the assumptions and information available at the time of our

review.

1.8    Permitting Requirements

Numerous permits are required by federal and state law for mining, processing, and related activities at the Ottawa Operation,

which U.S. Silica reports are in place or pending approval. New permits or permit revisions may be necessary from time to time to

facilitate future operations. Given sufficient time and planning, U.S. Silica should be able to secure new permits, as required, to

maintain its planned operations within the context of current regulations.

U.S. Silica reports having an extensive environmental management and compliance process designed to follow or to exceed

industry standards.

Mine safety is regulated by the U.S. Department of Labor’s Mine Safety and Health Administration (MSHA). MSHA inspects the

facilities a minimum of twice yearly. U.S. Silica’s safety record compares favorably with its regional peers.

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BOYD is not aware of any regulatory violation or compliance issue which would materially impact the silica sand reserve estimate.

1.9    Conclusions

It is BOYD’s overall conclusion that U.S. Silica’s estimates of silica sand reserves, as reported herein: (1) were prepared in

conformance with accepted industry standards and practices, and (2) are reasonably and appropriately supported by technical

evaluations, which consider all relevant modifying factors.

Given the lengthy operating history and status of evolution, residual uncertainty (future risk) for this operation is considered minor

under the current and foreseeable operating environment.

It is BOYD’s opinion that extraction of the silica sands reported herein is technically, legally, and economically achievable after the

consideration of potentially material modifying factors. The ability of U.S. Silica, or any mine operator, to recover all of the reported

silica sand reserves is dependent on numerous factors that are beyond the control of, and cannot be anticipated by, BOYD. These

factors include mining and geologic conditions, the capabilities of management and employees, the securing of required approvals

and permits in a timely manner, future silica sand prices, etc. Unforeseen changes in regulations could also impact performance.

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2.0    INTRODUCTION

2.1    Registrant

U.S. Silica is a US-based mining company headquartered in Katy, Texas. The company’s common stock is listed on the New York

Stock Exchange (NYSE:SLCA). U.S. Silica is actively engaged in the production and marketing of commercial silica sand and

performance materials (diatomaceous earth, calcium bentonite clay, calcium montmorillonite clay, and perlite products). Their whole

grain silica products are used as frac (proppant) sand for oil and natural gas recovery, and in the manufacture of glass, foundry, and

building products. U.S. Silica’s performance materials are used in: (1) filtration for foods and beverages, pharmaceuticals, and

swimming pools; (2) as additives in paint and coatings, plastics and rubber, and agriculture products; and (3) for bleaching, catalysis

and adsorption in edible oil processing, aromatics purification, and industrial and chemical applications. Additional information

regarding U.S. Silica can be found on their website: www.ussilica.com.

2.2    Terms of Reference and Purpose

U.S. Silica retained BOYD to complete an independent technical assessment of their internally-prepared silica sand resource and

reserve estimates and supporting information for the Ottawa Operation.

BOYD prepared this technical report summary for U.S. Silica in support of their disclosure of silica sand reserves for the Ottawa

Operation in accordance with S-K 1300. The purpose of this report is threefold: (1) to summarize material technical and

geoscientific information for the subject mining property, (2) to provide the conclusions of our technical assessment, and (3) to

provide a statement of silica sand resources and/or reserves for the Ottawa Operation.

BOYD’s findings are based on our detailed examination of the supporting geologic and other scientific, technical, and economic

information provided by U.S. Silica, as well as our assessment of the methodology and practices applied by U.S. Silica in

formulating the estimates of silica sand resources and reserves disclosed in this report. We did not independently estimate silica

sand resources or reserves from first principles.

We used standard engineering and geoscience methods, or a combination of methods, that we considered to be appropriate and

necessary to establish the conclusions set forth herein. As in all aspects of mining property evaluation, there are uncertainties

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inherent in the interpretation of engineering and geoscience data; therefore, our conclusions necessarily represent only informed

professional judgment.

The ability of U.S. Silica, or any mine operator, to recover all of the estimated silica sand reserves presented in this report is

dependent on numerous factors that are beyond the control of, and cannot be anticipated by, BOYD. These factors include mining

and geologic conditions, the capabilities of management and employees, the securing of required approvals and permits in a timely

manner, future sand prices, etc. Unforeseen changes in regulations could also impact performance. Opinions presented in this

report apply to the site conditions and features as they existed at the time of BOYD’s investigations and those reasonably

foreseeable.

This report is intended for use by U.S. Silica, subject to the terms and conditions of its professional services agreement with BOYD.

We also consent to U.S. Silica filing this report as a technical report summary with the SEC pursuant to S-K 1300. Except for the

purposes legislated under US securities law, any other uses of or reliance on this report by any third party is at that party’s sole risk.

2.3    Expert Qualifications

BOYD is an independent consulting firm specializing in mining-related engineering and financial consulting services. Since 1943,

BOYD has completed over 4,000 projects in the United States and more than 60 other countries. Our full-time staff comprises

mining experts in: civil, environmental, geotechnical, and mining engineering; geology; mineral economics; and market analysis. Our

extensive experience in silica sand resource and reserve estimation combined with our knowledge of the subject property, provides

BOYD an informed basis on which to opine on the reasonableness of the estimates provided by U.S. Silica. An overview of BOYD

can be found on our website at www.jtboyd.com.

The individuals primarily responsible for completing this technical assessment and the preparation of this report are by virtue of their

education, experience, and professional association considered qualified persons (QPs) as defined in S-K 1300.

Neither BOYD nor its staff employed in the preparation of this report have any beneficial interest in U.S. Silica, and are not insiders,

associates, or affiliates of U.S. Silica. The results of our assessment were not dependent upon any prior agreements concerning the

conclusions to be reached, nor were there any undisclosed understandings concerning any future business dealings between U.S.

Silica and BOYD. This report was prepared in return for fees based upon agreed commercial rates, and the payment for

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our services was not contingent upon our opinions regarding the project or approval of our work by U.S. Silica and its

representatives.

2.4    Principal Sources of Information

Information used in this assignment was obtained from: (1) files provided by U.S. Silica, (2) discussions with U.S. Silica personnel,

(3) records on file with regulatory agencies, (4) public sources, and (5) nonconfidential information in BOYD’s possession.

The following information was provided by U.S. Silica:

• Year-end reserve statements and reports for 2021 and 2022.
• Exploration records (e.g., drilling logs and lab sheets).
• Geologic databases of lithology and sand quality.
• Computerized geologic models.
• Mapping data, with:

Land ownership boundaries.
Infrastructure locations.

-
-
- Easement and right-of-way boundaries.
- Surveyed topography (surface elevation).

• Mine plans, production schedules, and supporting data.
• Overview of processing operations and detailed flow sheets.
• Copies of mining and operating permits.
• Historical information, including:

- Production reports.
-
Financial statements.
- Product sales and pricing.

Information from sources external to BOYD and/or U.S. Silica are referenced accordingly.

The data and work papers used in the preparation of this report are on file in our offices.

2.5    Personal Inspections

A site visit and inspection of the Ottawa Operation was completed on October 18, 2022,

by BOYD’s QPs responsible for the preparation of this report. The site visit included: (1) observation of the active mining operations,

(2) a tour of the mine site’s surface infrastructure, and (3) a tour of the process plant and truck loadouts. BOYD’s representatives

were accompanied by senior U.S. Silica engineering and management personnel who openly and cooperatively answered

questions regarding, but not limited

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to: site history; deposit geology; mining and processing operations; near- and long-range mining plans; and silica sand marketing.

2.6    Report Version

The silica sand resources and reserves presented in this Technical Report Summary are effective as of December 31, 2022. The

effective (i.e., “as of”) date of the report is December 31, 2022.

This is the third Technical Report Summary filed by U.S. Silica for the Ottawa Operation and supersedes the following previously

filed reports:

Westward Environmental; February 2022; Technical Report Summary Ottawa Site, Lasalle County, Illinois.

Westward Environmental; September 2022; Technical Report Summary Ottawa Site, Lasalle County, Illinois.

The user of this document should ensure that this is the most recent disclosure of silica sand resources and reserves for the Ottawa

Operation as it is no longer valid if more recent estimates have been issued.

2.7    Units of Measure

The US customary measurement system has been used throughout this report. Tons are short tons of 2,000 pounds-mass. Unless

otherwise stated, currency is expressed in US Dollars ($). Historic prices and costs are presented in nominal (unadjusted) dollars.

Future dollars values are expressed on a constant (unescalated) basis.

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3.0    PROPERTY DESCRIPTION

3.1    Location

U.S. Silica’s Ottawa Operation is a surface silica sand mining and processing operation located immediately west of the City of

Ottawa in LaSalle County, Illinois. The cities of Chicago and Peoria, Illinois, are located approximately 95 miles east-northeast and

75 miles southwest, respectively, of the Ottawa Operation.

The property is bisected by the Illinois River into the North Ottawa and South Ottawa sites. The mine offices, maintenance facilities,

processing plant, loadout facilities, and former mining pits are located on the North Ottawa site, while the active and future mining

areas are located on the South Ottawa site. The South Ottawa site includes three defined pits: South Ottawa, where current mining

is taking place, and the West Ottawa Pit and the Mississippi Sand Pit (future mining areas). A slurry line driven under the Illinois

River connects the two sites, and feeds ROM sand material from South Ottawa to the processing plant.

Geographically, the Ottawa Operation’s processing plant is located at approximately 41° 20' 45.19" N latitude and 88° 52' 33.11" W

longitude. Figures 1.1 (page 1-2) and 3.1, on the following page, illustrate the location and general layout of the Ottawa Operation.

3.2    Property Rights
U.S. Silica and its predecessors purchased the parcels of land—both surface and mineral rights—that currently comprise the
Ottawa Operation at various times in its history to underpin their long-term operational goals. Currently, the Ottawa Operation
comprises 68 parcels totaling approximately 2,072 acres of surface and minerals rights fully owned by U.S. Silica, as shown in Table

3.1.

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3.3    Encumbrances

3.3.1    Fees and Royalties

To maintain ownership of the Ottawa Operation properties, U.S. Silica must pay property taxes to the local government in LaSalle

County. To BOYD’s knowledge there are no liens against the properties.

It is BOYD’s understanding that there are no royalties, overriding or limited royalties, working interests, production payments, net

profit interests, or other mineral interests in the Ottawa Operation properties.

3.3.2    Permitting Requirements

Mining and processing activities on the Ottawa Operation properties are regulated by several federal and state laws. As mandated

by these laws and regulations, numerous permits are required for mining, processing, and other incidental activities. U.S. Silica

reports that necessary permits are in place or applied for to support immediate operations. New permits or permit revisions may be

necessary from time to time to facilitate future operations. Given sufficient time and planning, U.S. Silica should be able to secure

new permits, as required, to maintain its planned operations within the context of the current regulations. Permitting and permitting

conditions are discussed further in Chapter 17 of this report.

In BOYD’s opinion, U.S. Silica has demonstrated their ability and cooperation to align their operating plans with any permitting

requirements that may be encountered during the normal course of business.

BOYD is not aware of any current material violations or fines imposed by regulators on the Ottawa Operation.

3.3.3    Mining Restrictions

Several natural and man-made features have been identified in and around the South Ottawa site which may limit the mineable

areas of the property. As of this report, these features include:

Illinois Route 71 right-of-way.

• Setbacks from neighboring properties.
•
• East 1251st Road (Catlin Park Road) right-of-way.
• Catlin Salt Marsh.
• Ernat Salt Marsh.
• Brown’s Brook.
•
• Archeologically significant sites.

Jurisdictional wetlands and tributaries.

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U.S. Silica has included suitable setbacks in their mining plans to avoid disturbing these sensitive areas. As such, these areas have

been excluded from the estimates of silica sand resources and reserves presented herein.

3.3.4    Other Significant Factors or Risks

To the extent known to BOYD, there are no other significant factors and risks that may affect access, title, or the right or ability to

perform work on the Ottawa Operation property that are not discussed in this report. However, the reported silica sand resources

and reserves may be materially impacted by: U.S. Silica’s failure to comply with permit conditions and rules; delays in obtaining

required government or other regulatory approvals or permits; U.S. Silica’s inability to obtain such required approvals or permits; or

unforeseen changes in governmental regulations.

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4.0    PHYSIOGRAPHY, ACCESSIBILITY, AND INFRASTRUCTURE

4.1    Topography, Elevation, and Vegetation

The Ottawa Operation lies within the Bloomington Ridged Plain division of the Till Plains Section physiographic province of Illinois.

This region is generally characterized by low, broad, gently sloping ridges formed by glacial moraines, intertwined with wide regions

of relatively flat grasslands.

Surface elevations in and around the property range from approximately 460 ft above mean sea-level (AMSL) near the Illinois River,

to over 610 ft AMSL on the southern-most extents of the South Ottawa site where it abuts the Illinois River bluff.

Various streams and waterways are present in the immediate area, which drain into the Illinois River. The Ottawa South site

contains several wetlands and almost all areas north of the bluff are located within the flood plain of the Illinois River.

Land cover in the immediate area consists predominantly of a mixture of forest, crop/pastureland, and medium density rural areas

outside of the city of Ottawa—which is characterized as a medium-to-high density urban area.

4.2    Accessibility

General access to the Ottawa Operation is via a well-developed network of primary and secondary roads serviced by state and local

governments. These roads provide direct access to the mine site and processing facilities and are generally open year-round.

A dedicated rail spur connects the Ottawa Operation to BNSF and CXS Class 1 rail lines located to the north and east of the

property. Union Pacific and Norfolk Southern rail lines can be accessed utilizing truck transloading, if necessary.

Due to the operation’s location along the Illinois River, U.S. Silica also leases property to a privately-owned barge terminal, which

may also be utilized for transporting finished goods.

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4.3    Climate

Climate in and around the Ottawa Operation is characteristic for the midwestern US, with four seasons ranging from very cold and

snowy winters to hot and humid summers, with generally milder falls and springs. The average daily high temperatures typically

reach above freezing all 12 months of the year, while the low temperatures typically drop below freezing during 7 months of the

year. Winter temperatures typically range from 18 degrees Fahrenheit (° F) to 36° F, while summer temperatures usually range from

60° F to 84° F. Average annual precipitation for the area is approximately 37 inches of rain and 21 inches of snow.

In general, the operating season for the Ottawa Operation is year-round. Adverse weather conditions seldom limit mining,

processing, and loading operations; however, extreme weather conditions may temporarily impact operations. Periodic flooding is

possible during heavy rainfall.

4.4    Infrastructure Availability and Sources

The Ottawa Operation lies within a well-developed region of north-central Illinois and has been operating for over 100 years in a

region of mixed industrial and suburban development. The City of Ottawa has a population of almost 19,000 and over 500,000

people live in LaSalle County and the surrounding counites, according to 2021 US Census data.

Finished silica sand products from the Ottawa Operation are mainly transported to customer by rail and supported by U.S. Silica’s

extensive on-site rail-car loading, storage, and handling facility. Access to a well-maintained network of roads and a barge

terminal provide alternative transportation options.
Several regional airports are located within an hour’s drive from the Ottawa Operation, and the Chicago O’Hare and Midway

international airports are less than two hours away by car.

Reliable sources of electrical power, water, supplies, and materials are readily available. Electrical power is provided to the

operation by regional utility companies. Water is supplied by public water services, surface impoundments, or water wells. The

Ottawa Operation has an abundance of recycled slurry water and processing water available.

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5.0    HISTORY

5.1    Reserve Acquisition

The United States Silica Sand Company, a separate entity from U.S. Silica, established the first large-scale silica sand mining

operation near the town of Ottawa, on the southern side of the Illinois River in 1894. This company mined the St. Peter Sandstone

using a combination of blasting and hydraulic mining, in very much the same manner that the formation is mined today.

Edmund B. Thornton, a competitor to the United States Silica Sand Company, began a local silica sand mining operation on the

present day North Ottawa site in 1900 under the name Ottawa Silica Company. By the 1920’s, the Ottawa Silica Company had

taken over most of the silica sand production in the area, eventually resulting in the Thornton family buying out the United States

Silica Sand Company in 1928. The Thornton family continued to own and operate the Ottawa Silica Company until 1986, when the

company was sold to Rio Tinto Zinc, a large mining conglomerate based in London.

Rio Tinto Zinc merged the newly acquired Ottawa Silica Company with their Berkely Springs, West Virgina-based Pennsylvania

Glass Sand Company in January 1987, forming what is now U.S. Silica.

5.2    Exploration and Development

The Ottawa Silica Company was formed over 100 years ago to meet the demands of a small and local market segment. As industry

and mass production grew and evolved, the operation did as well, and it began selling silica sand into additional markets, such as

glass making, foundry casting, abrasives, building materials, and other segments over the years.

The grinding plant was built in the 1940’s to produce ground silica products. This plant utilizes dry ball mills to reduce silica sand

grains into fine-ground silica powders for use in various specialty markets for composite glasses, adhesives, fillers, sealants,

ceramics, and epoxies.

A significant example of changing markets affecting the Ottawa Operation occurred in the late 1990’s and early 2000’s, as the use

of silica sand in hydraulic fracturing of shales for oil and gas production began to increase drastically. Seeing demands for silica

sand shift in their market base and noting what looked to be a growing segment at the

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time, U.S. Silica shifted their production strategies to accommodate this market segment. In 2008, development of the Marcellus

Shale, and the subsequent additional demand for proppant sands resulted in various expansions being undertaken by U.S. Silica. In

order to be able to meet growing demand for proppant sands, the Ottawa Operation expanded its production capacity by 500

thousand tons per year in 2009. Demand for proppant sands continued to increase, and U.S. Silica again expanded the Ottawa

operations in 2011 by another 900 thousand tons per year, reaching the present-day production capacity of 3.3 million product tons

per year.

Exploration on the South Ottawa site began in 2000 as U.S. Silica began developing strategies in anticipation of having to move

production to the south side of the Illinois River. There is no record of any exploration being performed prior to 2000 on the South

Ottawa site. Exploration data for the mined-out areas in the North Ottawa site were not reviewed for this report.

The North Ottawa Pit was depleted of mineable sand by 2010, at which time mining operations were moved to the South Ottawa Pit.

A slurry line was driven from the eastern portion of the South Ottawa Pit area, under the Illinois River, and to the existing processing

plant which is located on the North Ottawa site. Operations continue in the original South Ottawa Pit today.

Again, considering future mine planning needs, U.S. Silica initiated a reserve expansion project in the spring of 2016, with the

objective of extending the life of the Ottawa Operation. To this end, U.S. Silica acquired a 314-acre parcel, known as the Mississippi

Sand Mine, located adjacent to the western border of the South Ottawa site.

U.S. Silica notes they have continually renovated and updated their facilities in order to improve operational efficiency and better

respond to changing market demands. These continuous process improvements have resulted in the operation’s ability to produce

multiple types of products using various processing methods (washing, hydraulic sizing, grinding, screening, and blending).

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6.0    GEOLOGICAL SETTING, MINERALIZATION, AND DEPOSIT

6.1    Regional Geology

The Ottawa Operation mines and processes material from the St. Peter Sandstone, which is a massive formation in areal extent

and thickness. The formation is found principally in the area drained by the Mississippi River and its tributaries, spanning north to

south from Minnesota to Arkansas and east to west from Illinois into Nebraska and South Dakota. On a regional basis, the St. Peter

Sandstone ranges in thickness from a few feet to over 1,200 ft, with a general thickness of 100 ft to 200 ft. Depths of the sandstone

range from a few feet to greater than 10,000 ft.

The St. Peter Sandstone is Middle Ordovician in age (around 460 million years old) and was deposited in an advancing marine
shoreline dominated by eolian dune and beach processes. Since the deposition, the formation has experienced several episodes of

subsidence and uplift.

Except where it has been removed by erosion, the St. Peter Sandstone covers most of the Illinois Basin at depths varying from a

few feet to almost 7,000 ft. The formation outcrops in four principal areas of northern Illinois: (1) the Ottawa-Utica-Millington area,

where it outcrops along the Illinois and Fox rivers; (2) the Oregon-Dixon area; (3) the Brookville-Harper area; and (4) the Calhoun

County area. In northern Illinois, the thickness of the formation can reach over 300 ft; however, it generally occurs as a 100 ft to 200

ft thick bed. Variations in the thickness of the St. Peter Sandstone are due to post depositional erosion and its highly irregular lower

boundary.

The St. Peter Sandstone is a super-mature quartz arenite (≈99% quartz) that consists primarily of well-sorted, fine- to medium-
sized, well-rounded quartz grains that are friable or weakly cemented and generally free from clay, carbonates, and heavy minerals.

On a regional basis, the formation exhibits grain size that generally ranges from coarser in the upper section to finer in the lower

section. As a rule, the lower portion of the formation is fine-grained with iron, alumina, and carbonate contamination increasing with

depth.

The St. Peter Formation is an important aquifer as well as a source of high purity silica sand.

6.2    Local Geology

6.2.1    Stratigraphy

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Ordovician and Pennsylvanian sedimentary strata comprise the uppermost stratigraphic units underlying the soils in and around the

Ottawa Operation. These units primarily include bedrock of, in ascending stratigraphic order, the Prairie du Chien, Ancell, Platteville,

and Galena groups of the Ordovician series, and the Pennsylvanian Carbondale Formation. The stratigraphic relationship between

these groups is presented in Figure 6.1 as follows.

The following text discusses the strata encountered near Ottawa in ascending depositional order.

Shakopee

The Shakopee Dolomite of the Prairie du Chien Group is composed of argillaceous to pure, very fine-grained dolomite with some

thin beds of medium-grained, cross-bedded sandstone, medium-grained dolomite, green to light gray shale, and buff siltstone.

St. Peter

The St. Peter Sandstone unconformably overlies the Shakopee Dolomite formation, and is composed of three members. The lower

unit, the Kress Member, consists of chert conglomerate with beds of red and green shale and medium- to coarse-grained

sandstone. The remainder of the St. Peter Sandstone is composed of well-rounded, well-sorted, medium- to coarse-grained

sandstone of the Tonti and Starved Rock Members,

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in depositional order. Locally, the upper part of the St. Peter Sandstone can be poorly consolidated, becoming more consolidated

with depth.

Glenwood

The Glenwood Formation is a highly varied unit of poorly sorted sandstone, impure dolomite, and green shale overlying the St.

Peter Sandstone. The sandstones have a distinctive bimodal, or “pudding stone,” texture, with medium grains of well-rounded

quartz sand, like those of the St. Peter Sandstone, but contained in a matrix of very fine sand and coarse silt. The Glenwood

sandstones also contain a variety of heavy minerals, including abundant garnet. This unit is generally not present in the immediate

vicinity of the Ottawa Operation but can be found south of the property.

Platteville and Galena

The Platteville and Galena Formations are often combined due to consisting mainly of carbonate sequences of limestone and

dolomite. These formations are present south of the Ottawa Operation, but not in the immediate vicinity.

Tradewater and Carbondale

These Pennsylvanian strata are predominantly clastic and contain subordinate amounts of coal and limestone. While this formation

is not found at the Ottawa Operation, it comprises the primary near-surface bedrock strata south of the bluffs that border the Illinois

River Valley.

Undifferentiated Quaternary Alluvium

Surface geology consists of what is mapped as the Quaternary Age Cahokia Alluvium, an unconsolidated interval of poorly sorted

silts, clays, and sand and gravels. Thickness of this unit varies greatly in the region but is very thin within the Illinois River Valley.

6.2.2    Structural Geology

The St. Peter Sandstone at Ottawa lies very near the surface (thereby creating favorable mining conditions) primarily for two

reasons. Firstly, one of the most prominent structural features in the Illinois Basin, the La Salle Anticlinorium, has uplifted the

sandstone formation from its original depositional position. Secondly, glacial floodwaters of the Late Wisconsin Episode carved the

upper reaches of the Illinois River Valley, removing most of strata overlying the St. Peter Sandstone, leaving the sandstone near the

land surface as a bedrock bench that is easily identifiable.

On the south bank of the Illinois River, the St. Peter Sandstone forms bluffs and outcrops in the valleys incident to the bluffs from

Ottawa to Little Rock, Illinois. In this area, the

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overlying formations are principally Pennsylvanian beds, though locally, as at the edge of the bluff in Starved Rock State Park and

near Little Rock, the sandstone is bare or is covered with a thin mantle of soil or glacial till.

6.3    Property Geology

The St. Peter Sandstone is the only strata of economic interest at the Ottawa Operation, and is very uniform in depositional nature

and continuity throughout much of the surrounding region. BOYD considers the subject silica sand deposit to be of low geologic

complexity. Furthermore, the geology of the St. Peter Sandstone is well understood after a lengthy history of commercial operations

at Ottawa.

Within the defined resource boundaries, the St. Peter Sandstone exhibits: (1) low depth of cover, (2) lateral continuity, (3) a

minimum thickness of 70 ft, (4) gentle dipping, and (5) minimal faulting. Figure 6.2, following this page, provides a map of the St.

Peter Sandstone thickness. A cross-section through the deposit is provided in Figure 6.3.

The two members of the St. Peter Sandstone—the coarser-grained upper Starved Rock and finer-grained lower Tonti members—

are easily identifiable and separable during mining and can be blended as required to meet product specifications. Deleterious

materials such as iron (which manifests as orange staining) are easily removed during mining and processing. The sandstone unit is

covered by a thin layer of overburden that is generally less than 20 ft thick.

The Ottawa Operation’s sands are generally characterized by a high silica content, high roundness and sphericity, white coloration,

and lack of deleterious material. The sandstone is very weakly cemented, allowing it to be mined hydraulically without the need for

crushing, which retains the well-rounded grain shape. Because of the monocrystalline structure, these sands have superior grain

strength when compared to other silica sands and are suitable for pressure applications generally up to the 9,000-pounds per

square inch (psi) range. These characteristics are responsible for the market popularity of the Ottawa Operation’s silica sand

products.

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7.0    EXPLORATION DATA

7.1    Background
The Ottawa Operation has an extensive history, over 100 years, of mining and producing of finished silica sand from the St. Peter

Sandstone. The Ottawa North site was depleted of silica sand reserves by 2010, by which time operations had commenced at the
Ottawa South site. All of the silica sand reserves reported herein are contained within the planned mining areas of the Ottawa South
site.

BOYD was provided source records (drilling logs, testing results, and core photographs) and a database compiling the results 225

drill holes, wells, field measurements, and test holes located in and around the South Ottawa site. Records indicate that these
exploration data were collected between 2000 and 2014.

An overview of U.S. Silica’s exploration and sampling standardized procedures was also provided, which summarizes

methodologies and techniques utilized during the various exploration programs completed at the Ottawa Operation.

7.2    Exploration Procedures
7.2.1    Drilling

Drill holes on the Ottawa South site were completed using various drilling procedures based on specific goals and data needs at

various stages of planning and developing the Ottawa Mine. Drilling methods utilized to delineate the sub-surface geology include

diamond core drilling, rotosonic drilling, and rotary auger drilling techniques. The various exploration campaigns completed, in

addition to outcrop mapping, site surveys, and review of United States Geological Survey and Illinois State Geological Survey

mapping, serve as the basis for evaluating the extents and geologic continuity of the St. Peter Sandstone underlying the Ottawa

South site.

BOYD’s review of the reported methodologies and procedures indicate the exploration data obtained and utilized by U.S. Silica for

the South Ottawa site were carefully and professionally collected, prepared, and documented, conforming with general industry

standards, and are appropriate for use of evaluating and estimating silica sand resources and reserves.

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7.2.2    Sand Quality Sampling

The Ottawa Operation’s sand quality sampling procedures followed standard industry practices, based on the information provided

and discussions held with U.S. Silica personnel. With a preference to utilize diamond core drilling methodologies, the general

procedures for sampling during any of the exploration programs, are as follows:

• Recovered drill cores are placed into core boxes and labeled with drill hole name, down hole footage, and recorded

thicknesses for each recovered core.

• Cores are geologically logged and photographed, with characteristics of the overall stratigraphy recorded while being boxed.
This allowed U.S. Silica to alter pre-determined drilling depths as the program progressed, in order to ensure the entire
target strata were sampled and collected.

• Boxed core samples were transported by U.S. Silica to one of their two internal laboratories—located in Berkeley Springs,

WV and Katy, TX—where they were checked in and split into 5-ft sample intervals for preparation and testing.

• Details on the expansion property exploration sampling techniques were not provided by Mississippi Sands to U.S. Silica.

However, available archival core samples were examined by U.S. Silica personnel, and the 5-ft sample intervals examined
seemed to be representative of the local geology. These samples were originally tested at a third-party (Bowser-Morner, Inc.)
laboratory in Dayton, Ohio. U.S. Silica obtained samples of the available archival drilling cores and transported and
performed their own testing at one of their internal laboratories prior to finalizing the acquisition of the Mississippi Sands
property.

U.S. Silica maintained control of exploration core samples throughout the entirety of each drilling campaign, from the point of

logging and boxing of recovered cores in the field, to transportation and delivery of core samples to their internal laboratories,

through performing preparation and analyses on each of the samples.

Available testing results were reviewed by BOYD during our assessment, and our review of the field and sampling procedures noted

above showed that the general description and sampling work were conducted to appropriate standards. Based on the stated

standards, both in the field and in the laboratory, BOYD considers the sample preparation and analytical procedures were adequate

for the purposes of evaluating and estimating silica sand resources and reserves at the Ottawa Operation.

7.2.3    Sand Testing

Samples obtained from the exploration campaigns completed at the Ottawa Operation were taken to one of the company’s in-house

laboratories, where they were prepared and analyzed for particle size distribution analyses. Samples were split and prepared

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following standardized company procedures—U.S. Silica’s ISO 9001 Quality System of Corporate Analytical Procedures—to ensure

analytical consistency throughout each of the various exploration campaigns. These procedures are designed to closely match the

operational capabilities of the Ottawa Operation’s processing plant.

Preparation of each sample consisted of initially splitting the recovered core in half using a chisel and hammer. One half of the core

is placed back into the core boxes which are then stored for archival purposes, while the other half of the core is further prepared

and processed for lab testing purposes.

Analysis samples were then crushed, quartered, and mixed to create a uniform and representative mixture of the core interval, and

are then divided into 1,000-to-5,000-gram samples, depending on the type and amount of testing to be performed. The desired

sample size is then run through various crushing techniques to disaggregate the sand grains and fine materials as much as possible

before beginning the washing and scrubbing procedures.

An approximately 1,500-gram sample is then obtained and washed before being run through a scalping procedure to remove

coarse (+16-mesh size for proppant sand product testing; +30-mesh size for industrial product testing) particles. This process

primarily removes the oversize “coarse waste” size fraction, leaving behind the material that would typically be washed in the wet

processing plant. The remaining material is weighed and labeled as a “washed sample”.

The washed sample is further prepared by simulating the wet processing plant conditions, which consist of placing a sample into

scrubbers for three minutes, rinsing and decanting, and then drying to arrive at a “scrubbed sample”, which represents material that

the wet processing plant would prepare before being run through a drying plant.

The scrubbed samples are then dried and analyzed following API/ISO standards for particle size distribution analysis and then API

RP 19C/ISO-13503-2 standard testing for proppant materials used in fracturing and gravel-packing operations.

7.2.4    Other Exploration Methods

There were not any other methods of exploration (such as airborne or ground geophysical surveys) reported for the Ottawa

Operation.

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7.3    Exploration Results

7.3.1    Summary of Exploration

A total of 225 drill holes were completed in and around the South Ottawa area. The distribution of these drill holes is shown on

Figure 7.1, on the next page.

As mentioned, the 225 drill holes include a variety of drill holes, wells, field measurements, and test holes. BOYD’s review

determined that 102 holes penetrated the full depth of the St. Peters Sandstone and were supported by suitable lithologic and sand

quality records. Lithologic data from many of the shorter holes (i.e., those which did not penetrate the entire thickness of the

sandstone strata), we used to estimate the thickness of the overburden material over the South Ottawa site.

General descriptive statistics for the St. Peter Sandstone, and overburden material are provided in Table 7.1, below.

These data confirm the generally uniform nature of the deposit underlying the South Ottawa site and support the interpretation of

the sandstone’s thickness illustrated in Figure 6.2 (page 6-5).

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7.3.2    Silica Sand Quality

The Ottawa Operation produces a wide variety of proppant sand and specialty silica sands products for numerous customers. While

not all of the finished products must adhere to a published set of specifications, U.S. Silica utilizes samples obtained during

exploration to ascertain the suitability of the mineable sandstone for producing the various materials it supplies to customers.

Particle size distribution and iron content are noted as the primary drivers of mine planning at the Ottawa Operation. Particle size

distribution within the sandstone, necessitates the concurrent mining of multiple areas of the mine to ensure supply of appropriately

sized material to the processing plant. Similarly, as iron content increases near the top and bottom of the sandstone, this material

must be discarded or blended with higher quality sand before processing.

U.S. Silica performs testing at their laboratories for API/ISO specifications; however, no data were made available for our review.

Historically, API RP 19C/ISO 13503-2 proppant sand characteristics were strictly used to determine the suitability of a sand product

for use during fracking stages of oil and gas well development. Over time, these specifications have become merely guidelines and

the suitability of a proppant sand product is now determined by the end user. Indeed, many end users test the products that they

purchase to determine if they meet their own internal specifications. BOYD notes that U.S. Silica has demonstrated commercial

success in producing and marketing their finished silica sand products; as such, it is BOYD’s opinion that sand quality data provided

are representative and suitable for the estimation of silica sand resources and reserves.

7.3.3    Grain Size Distribution

Grain size distribution was analyzed according to API RP 19C/ISO 13503-2, Section 6.

A table of weighted average grain size distribution of the in-situ sand deposit, based on laboratory testing results, is shown in Table

7.2, below.

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The preceding table highlights the relative fineness of the sand found within the Ottawa South Property, indicating a majority of the

sand particles are concentrated between the “passing 40-mesh” and “retained 140-mesh” size fraction. Accordingly, the

predominant marketable proppant sand product consists of the 40/140-mesh sand.

7.3.4    Grain Shape (Sphericity and Roundness)

Grain shape is defined under ISO 13503-2/API RP19C, Section 7. Under this standard, recommended sphericity and roundness

values for proppants are 0.6 or greater. As part of the grain shape analysis, the presence of grain clusters (weakly cemented grain

aggregates) and their approximate proportion in the sample are reported.

While individual sample testing results for the Ottawa Operation’s deposit were not available for review at the time of this report, it is

important to note that the St. Peter Sandstone is well studied and widely known to consistently exhibit the general characteristics of

being a fine-to-medium grained, well-rounded, and well-sorted sandstone comprised primarily of weakly cemented and

extraordinarily pure quartz grains that contain little-to-no deleterious materials within the sandstone matrix.

U.S. Silica has also produced and sold sand into various oil and gas basins, where ultimately the sand has been shown to meet

customer specifications.

7.3.5    Crush Resistance

Crush resistance is a key test that determines the amount of pressure a sand grain can withstand under laboratory conditions for a

two-minute duration. It is analyzed according to ISO 13503-2/API RP19C, Section 11. Under this standard, the highest stress level

(psi) in which the proppant produces no more than 10% crushed fine material is rounded down to the nearest 1,000 psi and

reported as the “K-value” of the material.

The Ottawa Operation’s silica sand products are noted for exhibiting high crush strengths.

7.3.6    Mineralogical Analyses

Mineralogical analyses were performed via x-ray fluorescence to determine the concentrations of various minerals present within

the sandstone matrix. Testing determined that the minerals present in the sandstone matrix will generally be removed during

processing of the mined silica sand. Mineralogical testing was conducted on a composited interval of the entire mineable interval

from a given drill hole.

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7.4    Data Verification

For purposes of this report, BOYD did not verify historic drill hole data by conducting independent drilling. It is customary in

preparing similar mining resource and reserve estimates to accept basic drilling and sample quality data as provided by the client

subject to the reported results being judged representative and reasonable.

BOYD’s efforts to judge the appropriateness and reasonability of the source exploration data included reviewing representative

samples of provided drilling logs, sampling procedures, sand quality testing results, and discussing aspects of developing the

operation with U.S. Silica personnel during our site visit. Reviewed drilling records were compared with their corresponding

database records for transcription errors; of which none were found. Lithologic and sand quality data points were compared via

visual and statistical inspection with geologic mapping and cross-sections.

7.5    Adequacy of Exploration and Sampling

BOYD’s review indicates that in general, U.S. Silica has performed an acceptable level of drilling and sampling work at the Ottawa

Operation. The work completed has been done by competent personnel in a manner consistent with industry practices. The amount

of data available, combined with extensive knowledge of the St. Peter Sandstone, are sufficient to confirm deposit uniformity and

continuity throughout the South Ottawa area. Similarly, BOYD’s review of testing data provided by U.S. Silica suggests that the

analyses completed are generally appropriate to determine silica sand characteristics and determine the subsequent quality of

finished silica sand products. As such, it is BOYD’s opinion that the exploration and sampling data are suitable for use in the

estimation of silica sand resources and reserves for the Ottawa Operation.

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8.0    SAMPLE PREPARATION, ANALYSIS, AND SECURITY

The reader is referred to Sections 7.2 and 7.3 of this report for details regarding sample preparation, analysis, and security.

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9.0    DATA VERIFICATION

BOYD, by way of the data verification processes described in various sections of this report, has used only that data, which were
deemed by the QPs to have been generated with proper industry standard procedures, were accurately transcribed from the original

source and were suitable to be used for the purpose of preparing estimates of silica sand resources and reserves.

BOYD’s subject-specific data verification efforts and our conclusions arising therefrom are discussed in the following sections of this
report:

Based on our review, it is BOYD’s overall conclusion that the information made available to us at the time of this report is
representative and reliable for use in estimating the silica sand resources and reserves of the Ottawa Operation.

BOYD is not aware of any other limitations on nor failure to conduct appropriate data verification.

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10.0    MINERAL PROCESSING AND METALLURGICAL TESTING

Please refer to Chapter 7 for information regarding mineralogical and grain size distribution testing.

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11.0    SILICA SAND RESOURCE ESTIMATE

11.1    Applicable Standards and Definitions

Unless noted, silica sand resource estimates disclosed herein are done so in accordance with the standards and definitions

provided by S-K 1300. It should be noted that BOYD considers the terms “mineral” and “silica sand” to be generally interchangeable

within the relevant sections of S-K 1300.

Estimates of mineral resources are always subject to a degree of uncertainty. The level of confidence that can be applied to a

particular estimate is a function of, among other things: the amount, quality, and completeness of exploration data; the geological

complexity of the deposit; and economic, legal, social, and environmental factors associated with mining the resource. By

assignment, BOYD used the definitions provided in S-K 1300 to describe the varying degree of certainty associated with the

estimates reported herein.

The definition of mineral resource provided by S-K 1300 is:

Mineral resource is a concentration or occurrence of material of economic interest in or on the Earth's crust in such form,
grade or quality, and quantity that there are reasonable prospects for economic extraction. A mineral resource is a
reasonable estimate of mineralization, taking into account relevant factors such as cut-off grade, likely mining dimensions,
location or continuity, that, with the assumed and justifiable technical and economic conditions, is likely to, in whole or in part,
become economically extractable. It is not merely an inventory of all mineralization drilled or sampled.

Estimates of mineral resources are subdivided to reflect different levels of geological confidence into measured (highest geologic

assurance), indicated, and inferred (lowest geologic assurance). Please refer to the Glossary of Abbreviations and Definitions for

the meanings ascribed to these terms.

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11.2    Silica Sand Resources

11.2.1    Methodology

Based on provided information, U.S. Silica’s geologic modeling and silica sand resource estimation techniques generally consist of

following:

1. The top and bottom elevations of the quartzose (high-quality) St. Peter Sandstone interval is interpreted from drill hole records
and sand particle size analyses. Strata above the interpreted sandstone interval are considered overburden (waste). Strata
below the sandstone unit—generally, the Kress cherty shale or Shakopee Dolomite—are also considered waste.

2.

Interpreted drill hole records are compiled and validated. Strata thicknesses are aggregated, and sand particle size analyses of
the sandstone unit are composited for each data point. The compiled drill hole data are imported into GEOVIA Surpac™
geologic modeling and mine planning software.

3. A geologic block model of the deposit is developed using industry standard stratigraphic modeling methods. The geologic model

delineates overburden, and the top and bottom of the mineable sandstone horizon.

4. Contiguous regions of mineable sandstone are outlined (applying criteria discussed below in Section 11.2.2), and LOM pit shells

are created

5. Estimates of in-place overburden waste and mineable sandstone volumes are derived from the LOM pit shells and recent

topographic (surface elevation) surveys.

6. An in-place sandstone dry density of 135 pounds per cubic foot is used to convert the in-place sand volumes to in-place sand

tons.

11.2.2    Estimation Criteria

Development of the silica sand resource estimate for the Ottawa Operation assumes mining and processing methods and

equipment which have been utilized successfully at the site for decades.

The target mining horizon, the St. Peter Sandstone, underlies the entirety of U.S. Silica’s property at the Ottawa Operation, and is

manifested as a continuous, flat-lying sedimentary rock unit with consistent depth and thickness. While the sandstone exhibits

vertical variations in quality, all of the unit is mined and sold under various product specifications. The high-quality sandstone is

easily distinguished from the surrounding lower-quality or non-sandstone rock units, aiding in the interpretation of the mineable

horizon. Additionally, the Ottawa Operation has a lengthy commercial history of producing numerous products with various size and

quality specifications, allowing nearly all of the identified mineable sandstone interval to be utilized. Based on the uniformity of the

sand deposit being mined, cut-off grades, strip ratio, and other typical mining factors do not define economic mineabilty. Production

of silica sand is driven by

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market demand. Silica sand production can be modified in response to that demand. As such, the application of minimum mining

thicknesses, maximum stripping ratios (the ratio of waste to sandstone excavated), or cut-off grades is not generally considered in

the estimation of silica sand resources for the Ottawa Operation.

The limits of the silica sand resources are constrained to those portions of the interpreted sandstone deposit that:

• Are reasonably defined by available drilling and sampling data.

• Contain products that meet generally accepted specifications.

• Honor any legal mining constraints (e.g., property boundaries, environmental setbacks, utility and infrastructure setbacks, etc.).

• Adhere to physical mining constraints.

• Contain products that can be sold at a profit (i.e., be economic).

U.S. Silica applied the following offsets to define the silica sand resource boundaries for the Ottawa Operation:

•
•
•

25-ft buffer around wetlands and streams.
200-ft offsets from neighboring property boundaries.
160-ft right-of-ways around roadways.

The following mine design criteria are used to develop the pits shells which constrain the estimated silica sand resources:

• Slopes of 33% in topsoil, clay, gravel, or unconsolidated overburden materials.

• Slopes of 70° in sandstone.

• A minimum of a 10-ft wide safety bench is left at the alluvium/rock and rock/sand contacts.

• A minimum of a 25-ft wide safety bench is left at approximately 425 feet AMSL.

•

The bottom of mineable resources is by pit design at a variable elevation to allow proper drainage, and is limited to 5 ft above
the underlying shale/dolomite or a minimum elevation of 378 ft AMSL, whichever is higher.

Silica sand resources for the Ottawa Operation are assessed for reasonable prospects for eventual economic extraction by

reporting only that material which has been subsequently converted to silica sand reserves after the application of all material

modifying factors.

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BOYD has reviewed the criteria employed by U.S. Silica in developing their estimates of silica sand resources. The parameters are

supported by historical results and align with those employed at similar operations. As such, it is BOYD’s opinion that the stated

criteria are reasonable and appropriate for the estimation of silica sand resources at the Ottawa Operation.

11.2.3    Classification

Geologic assuredness is established by the availability of both structural (thickness and elevation) and particle size distribution for

the St. Peter Sandstone. Classification is generally based on the concentration or spacing of exploration data, geological

understanding, continuity of mineralization relative to the style of mineralization, and uncertainty with the exploration data. Table

11.1 provides the general criteria employed in the classification of the silica sand resources.

Extrapolation or projection of resources in any category beyond any data point does not exceed half the point spacing distance.

BOYD reviewed the classification criteria employed by U.S. Silica with regards to data density, data quality, geological continuity

and/or complexity, and estimation quality. The St. Peter Sandstone is well-known and of low geologic complexity. We believe these

criteria appropriately reflect their implied levels of geologic assurance with respect to the estimation of silica sand resources.

Mineable sand resources on the property are well-defined throughout all areas of the mine plan. Observed drill hole spacing

averages approximately 500 ft through a majority of the active mining area, with future mining areas exhibiting a general drill hole

spacing averaging approximately 750 ft to 1,250 ft.

    JOHN T. BOYD COMPANY

11-5

11.2.4    Silica Sand Resource Estimate

Resource estimates of in-place silica sand at the Ottawa Operation as of December 31, 2022, as reported by U.S. Silica are shown

in Table 11.2 below.

As shown, U.S. Silica controls approximately 93 million in-place tons of measured and indicated silica sand resources, inclusive of

silica sand reserves. In addition, they control approximately 88,000 in-place tons of inferred silica sand resources. Silica sand

resources are not silica sand reserves and do not have demonstrated economic viability.

The silica sand resources shown under the “Planned” column of Table 11.2 include only those in-place tons which are included in

U.S. Silica’s LOM plan for the Ottawa Operation and therefore considered for conversion to silica sand reserves. The silica sand

resources shown under the “Additional” column of Table 11.2 have not been included in the LOM plan and are considered exclusive

of (i.e., “in addition to”) the reported silica sand reserves. These “Additional” silica sand resources are considered to have prospects

for eventual economic extraction by virtue of their similarity, in terms of demonstrated extraction methods and expected finished

product qualities, to those converted to silica sand reserves. However, further studies are required to convert the “Additional” silica

sand resources to silica sand reserves.

11.2.5    Validation

BOYD was provided with U.S. Silica’s exploration data, geologic models, and volumetric estimates. We have reviewed this

information, on a representative basis, by:

• Verifying the accuracy of geologic model inputs by comparison with drilling logs and laboratory reports.

• Comparing the geologic model with compiled drilling data.

    JOHN T. BOYD COMPANY

11-6

• Preparing a stratigraphic grid model of the sandstone unit and independently estimating pit shell volumes.

It is BOYD’s opinion that the geologic model is representative of the informing data and that the data are of sufficient quality to

support the silica sand resource estimate provided herein. Furthermore, it is our opinion that the estimation methods and criteria

employed are both appropriate and reasonable for the deposit type and proposed extraction methods.

BOYD is not aware of any technical, legal, economic, or other relevant factors that could materially affect the silica sand resource

estimate. The accuracy of silica sand resource estimate is, in part, a function of the quality and quantity of available data and of

engineering and geological interpretation and judgment. Given the data available at the time this report was prepared, the estimates

presented herein are considered reasonable. However, they should be accepted with the understanding that additional data and

analysis available after the date of the estimate may result in a change to the current estimate. These revisions may be material.

There is no guarantee that all or any part of the estimated resources will be recoverable.

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    JOHN T. BOYD COMPANY

12-1

12.0    SILICA SAND RESERVE ESTIMATE

12.1    Applicable Standards and Definitions

Unless noted, silica sand reserve estimates disclosed herein are done so in accordance with the standards and definitions provided

by S-K 1300. It should be noted that BOYD considers the terms “mineral” and “silica sand” to be generally interchangeable within

the relevant sections of S-K 1300.

Estimates of mineral reserves are always subject to a degree of uncertainty. The level of confidence that can be applied to a

particular estimate is a function of, among other things: the amount, quality, and completeness of exploration data; the geological

complexity of the deposit; and economic, legal, social, and environmental factors associated with mining the reserve. By

assignment, BOYD used the definitions provided in S-K 1300 to describe the varying degree of certainty associated with the

estimates reported herein.

The definition of mineral reserve provided by S-K 1300 is:

Mineral reserve is an estimate of tonnage and grade or quality of indicated and measured mineral resources that, in the
opinion of the qualified person, can be the basis of an economically viable project. More specifically, it is the economically
mineable part of a measured or indicated mineral resource, which includes diluting materials and allowances for losses that
may occur when the material is mined or extracted.

Estimates of mineral reserves are subdivided to reflect geologic confidence, and potential uncertainties in the modifying factors, into

proven (highest assurance) and probable. Please refer to the Glossary of Abbreviations and Definitions for the meanings ascribed

to these terms.

    JOHN T. BOYD COMPANY

Figure 12.1, below, illustrates the relationship between mineral resources and mineral reserves.

12-2

Figure 12.1: Relationship Between Mineral Resources and Mineral Reserves

By industry convention, silica sand reserves are presented on two bases: mineable and saleable. Mineable reserves represent the

ROM tonnage available for excavation and processing. Saleable reserves represent the tonnage of finished silica sand available for

sale after processing the mineable reserves.

12.2    Silica Sand Reserves

12.2.1    Methodology

Estimates of silica sand reserves for the Ottawa Operation are derived contemporaneously with estimates of silica sand resources.

The Ottawa Operation utilizes commercially proven mining and processing methods to extract and process silica sand from the

subject property. The operation’s production plans are revised periodically to assure that the conversion of in-place sand to saleable

product are: (1) in reasonable conformity with present and recent historical operational performance, and (2) reflective of expected

mining and processing operations.

    JOHN T. BOYD COMPANY

12-3

To derive estimates of mineable tons and saleable product tons (i.e., proven and probable silica sand reserves), the following

modifying factors were applied to the in-place measured and indicated silica sand resources underlying the respective mine plan

areas:

• A 95% mining recovery factor, which assumes that 5% of the mineable (in-place) silica sand resource will not be recovered for
various reasons. Applying this recovery factor to the in-place resource results in the estimated ROM sand tonnage (i.e., the
mineable silica sand reserves) that will be delivered to the wet process plant.

• An overall 86.5% processing yield. This factor accounts for removal of out-sized (i.e., larger than 20-mesh and smaller than 140-

mesh) sand and losses in the wet and dry processing plants due to minor inefficiencies.

The overall product yield (after mining and processing losses) for the Ottawa Operation is estimated at approximately 82.2%. That

is, for every 100 tons of in-place silica sand, approximately 82 tons will be recovered and sold as product. Mining recovery and

processing yield factors are derived from historical operating results.

Economic availability of the silica sand reserves is established by the financial analysis presented in Chapter 19. A long-range

average selling price of $42.37 per product ton has been used to estimate silica sand reserves for the Ottawa Operation.

12.2.2    Classification
Proven and probable silica sand reserves are derived from measured and indicated silica sand resources, respectively, in
accordance with S-K 1300. BOYD is satisfied that the stated silica sand reserve classification reflects the outcome of technical and

economic studies. Figure 12.2, following this page, illustrates the classification of the silica sand reserves at the Ottawa Operation.

    JOHN T. BOYD COMPANY

12-4

    
12-5

12.2.3    Silica Sand Reserve Estimate
U.S. Silica’s estimated surface mineable silica sand reserves for the Ottawa Operation total 78.9 million saleable product tons, as of

December 31, 2022. The silica sand reserves reported in Table 12.1, below, are based on the approved LOM plan which, in BOYD’s
opinion, is technically achievable and economically viable after the consideration of all material modifying factors.

All of the reported silica sand reserves wholly owned by U.S. Silica.

The silica sand reserves of the Ottawa Operation are well-explored and defined. It is our conclusion that over 98% of the stated

reserves can be classified in the proven reliability category (the highest level of assurance) with the remainder classified as

probable. Given the geologic uniformity and history of mining the St. Peter Formation on the Ottawa Operation properties, it is

reasonable to assume that the small portion of probable reserves will be converted to proven reserves upon completion of additional

exploration and testing.

The Ottawa Operation has a well-established history of mining, processing, and selling silica sand products into various markets.
BOYD has assessed that sufficient studies have been undertaken to enable the silica sand resources to be converted to silica sand
reserves based on current and proposed operating methods and practices. Changes in the factors and assumptions employed in
these studies may materially affect the silica sand reserve estimate.

The extent to which the silica sand reserves may be affected by any known geological, operational, environmental, permitting, legal,
title, variation, socio-economic, marketing,

    JOHN T. BOYD COMPANY

12-6

political, or other relevant issues has been reviewed as warranted. It is the opinion of BOYD that U.S. Silica has appropriately
mitigated, or has the operational acumen to mitigate, the risks associated with these factors. BOYD is not aware of any additional
risks that could materially affect the development of the silica sand reserves.

Based on our independent review, we have a high degree of confidence that the estimates shown in this report accurately represent
the available silica sand reserves controlled by U.S. Silica, as of December 31, 2022.

12.2.4    Reconciliation with Previous Estimates
When comparing U.S. Silica’s silica sand reserve estimates as of December 31, 2022, with the estimates presented  for December
31, 2021, we note a net decrease of approximately 8.7 million mineable tons resulting from: (1) depletion due to mining of
approximately 3.2 million mineable tons, and (2) revisions to mine plans resulting in deductions of approximately 5.5 million
mineable tons. BOYD does not consider these deductions, either individually or combined, to represent material changes to the
silica sand reserves of the Ottawa Operation.

1

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1
 U.S. Silica did not present reserves on a Saleable Tons basis for the 2021 financial year.

    JOHN T. BOYD COMPANY

13-1

13.0    MINING METHODS

13.1    Mining Operations

Surface silica sand mining has been conducted at the Ottawa Operation for over 100 years. Recent and current mining operations

are located in the South Ottawa Pit, on the south bank of the Illinois River.

In and around the Ottawa Operation, the St. Peter Sandstone generally exhibits a shallow depth, flat altitude, and consistent

thickness. These characteristics favor conventional surface mining techniques. Since the target sandstone formation does not

extend below the water table, the quarry is ‘dry-mined’ using truck and shovel mining methods. Mining occurs in a stair-like fashion

to recover sand from the top of the formation (in elevation) down to the lowest practical elevation (generally 5 ft from the bottom of

the St. Peter Sandstone).

The thin overburden, including topsoil, cap rock and vegetation, is cleared and transported to several mined-out areas in pit where it

is stockpiled for future reclamation needs. The material is poorly consolidated and thus drilling and blasting is typically not needed

for this stage of the mining operations. Overburden removal is performed, as required (usually one year in advance of sand mining),

by third party contractors and does not appear to hinder sand mining to any appreciable degree.

Once the overburden has been stripped, the poorly cemented sandstone is drilled and blasted in a series of benches between 40 to

75 ft high. Drilling and blasting are performed by local third-party contractors several times a year depending on production

requirements.

An excavator or front-end loader is used to load the shot sandstone into articulated haul trucks for transport to a “monitor station”

where the material is further broken down

    JOHN T. BOYD COMPANY

using high-pressure water to create a sand/water slurry. Figure 13.1, below, shows the loading operations in the South Ottawa Pit.

13-2

The slurry is transported under the Illinois River to the processing plant via a series of pumps and high-density polyethylene (HDPE)

pipes. A bulldozer is used to push any stockpiled rock in this area towards the monitor. Large stockpiling capacity at the monitor

station can help alleviate ROM sand supply fluctuations caused by minor disruptions in mining activities.

After the slurry material is transported to the processing plant, the water is recycled and returned to the mine site for reuse. The

pipes are positioned under the roadways to the north of the pit and under the Illinois River through lines which were drilled by

directional boring methods. Booster pump stations along the slurry line allows the sand to stay in suspension. This method of mining

and transportation has proven to be very effective since operations commenced in the South Ottawa Pit.

The mine generally operates year-round.

    JOHN T. BOYD COMPANY

13-3

13.2     Mine Equipment and Staffing

13.2.1     Mine Equipment

The primary mobile equipment involved in sand excavation includes:

Four John Deere 460E class articulated trucks.

• One Volvo 480EC Excavator.
•
• One John Deere 444 Loader
• One Caterpillar D8 Dozer.
• One John Deere 1050 Dozer.
Two Volvo 350F Loaders.
•
• A water truck and other ancillary equipment.

The mobile equipment fleet is comprised of both leased and owned equipment. Regular maintenance of mobile equipment is

performed by U.S. Silica personnel at the Ottawa facility. Major rebuilds or repairs are performed offsite at third-party repair facilities.

If maintained in good condition, the mobile equipment fleet should be capable of achieving production levels required by the LOM

plan.

13.2.2     Staffing

The Ottawa Operation is staffed by 145 hourly and salaried personnel. A breakdown of employees by classification is provided in

Table 13.1.

Hourly employees are represented by the United Steelworkers of America.

Most employees live in and around the City of Ottawa. Except for a drop in employment in 2020 (attributed to poor market

conditions during the COVID pandemic), staffing levels across the operational sites have largely remained consistent. The

workforce can be expanded or reduced based on market and seasonal demands.

13.3     Engineering and Planning

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13-4

The primary mine planning consideration is the safe, economical, and regular supply

of raw high-quality sand feed to the processing plant. In commercial mining terms, the quantities of overburden removed, and sand

mined each year at the Ottawa Operation are considered modest. The sandstone deposit affords easy access with its shallow depth

and large areal extent. As such, mining plans for the Ottawa mine are relatively simple and very flexible, able to be modified based

on demand in a relatively short time frame.

Geotechnically, the St. Peter Sandstone is relatively competent and the mining depths so shallow such that slumping, or collapsing,

has not been a detriment to the mining process. The pit design parameters discussed in Section 11.2.2 have been used with

success at the operation for decades.

Excessive inflow of groundwater into the pit is not expected. As such, dewatering before or during mining activities should be

manageable with drainage ditches and sumps. Flood waters from the adjacent Illinois River are a manageable risk. Onsite water

ponds can be used to hold any excessive ground or storm water.

13.4     Mining Sequence and Production

Mining of the St. Peter Sandstone at the Ottawa Operation commenced shortly after the founding of the Ottawa Silica Company in

1900 and has continued, without lengthy disruptions, to the present day. Over the past seven years, the operation has mined over

24 million tons of raw sand. During late 2019 and 2020, production was reduced from approximately 4 million tons per year to under

2.5 million tons in response to decreased

    JOHN T. BOYD COMPANY

customer demand due to the COVID-19 pandemic. Production rebounded in 2021 and 2022, and is forecasted to rise in the LOM

plan as illustrated in Figure 13.2, below.

13-5

The proposed mining sequence is illustrated in Figure 13.3, on the following page. As shown, the proposed mining sequence

anticipates that the remaining northern half of the South Ottawa Pit will be mined out over the next three years (by 2025).

Production will then shift to the southern half of the South Ottawa Pit and commence in a general north to south, then east to west

direction until 2031. At which point, mining on the West Ottawa Pit located on the other side of Browns Brook will commence in an

east to west, then north to south direction until sometime prior to 2042. Mining on the Mississippi Sand Mine, located west of the

county road bisecting the property, will begin on or before 2042 in an east to west direction and mining will conclude on the south-

east corner of the track sometime in 2047. Reclamation will occur concurrently with production as exhausted mining areas are

returned to agreed-upon final design.

BOYD reviewed the LOM plans for U.S. Silica’s Ottawa Operation to determine whether the plans: (1) utilize generally accepted

engineering practices, and (2) align with historical and industry norms. Based on our assessment, it is BOYD’s opinion that the

forecasted production levels for the Ottawa Operation are reasonable, logical, and consistent with typical sandstone surface mining

practices in the St. Peter Sandstone and historical results achieved by U.S. Silica.

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    JOHN T. BOYD COMPANY

13-6

    
13-7

    
14-1

14.0    PROCESSING OPERATIONS

14.1    Overview

The Ottawa Operation’s processing plant is located on the north shore of the Illinois River. U.S. Silica purchased the plant in 1987,

when it acquired the Ottawa Operation. The plant has been upgraded and expanded several times since its initial construction.

The production of finished silica sand begins when the plant receives a slurry of raw sand and water from the mine. From this slurry,

multiple products are generated through various wet and dry processing methods. Figure 14.1, on the next page, presents a

simplified process flow from the mine to the product distribution.

Currently the plant runs 24 hours a day, 365 days a year and has a nominal capacity of 3.29 million tons of finished sand per year.

Plant capacity is limited by the ability to separate fine silica sand and by permit restrictions tied to drying capacity.

BOYD is unaware of any reported interruptions, outages, shortages, or failures related to processing operations which have

materially affected the Ottawa Operation. Given the operation is well-established, we believe the risk of such events materially

affecting the estimates of silica sand reserves presented herein is low.

14.1.1    Wet Processing Plant

The Wet Processing Plant was originally built in 1975 and underwent expansions in 2009 and 2011. The Wet Processing Plant does

not produce any finished goods, but instead supplies feed-materials to other processing operations.

The plant receives its raw sand feed through the slurry pumping system from the mine. The slurry from the mine is passed through

a material washer to remove the very fine size fractions (mostly clays) which are too small to include in salable products. These very

fine particles, or tailings, are separated from the plant feed and are sent to settling ponds where the water is recovered for future

use. From here the plant feed passes through a bank of hydrosizers, hydro-cyclones, and vacuum filters to remove excess water.

This water is also reclaimed for future use.

    JOHN T. BOYD COMPANY

14-2

    
14-3

By this point, the sand has been separated into coarse and fine particle size fractions which are processed in dedicated, parallel
coarse and fine circuits based on the sizes of their intended final use. The wet silica sand streams are then dried in four fluidized

bed dryers where the dried silica sand is processed as whole grain silica in the Sizing and Fine Sand Plant or sent to the Grinding
Mill for production of ground silica products. One dryer is dedicated to the coarse-sand stream and three to the fine-sand stream.

14.1.2    Sizing and Fine Sand Plant
The Fine Sand Plant was built in the 1950’s and is used to produce whole grain silica sand products. Whole grain products are
shipped primarily to the foundry, glass, and hydraulic fracturing industries.

Drying of whole grain silica begins by processing portions of the coarse-sand stream and the fine-sand streams from the Wet
Processing Plant. This material is then sorted into various size fractions, then prepped for shipment by either a bulk carrier (rail or
truck) or is loaded into bags in the bagging plant and warehoused for specific end-use markets.

14.1.3    Grinding Mills
The Grinding Plant was built in the 1940’s and utilizes dry ball mills to reduce whole-grain silica sand into ground-silica products for
sale to the specialty and composite glass, fused silica, adhesives, and countertop markets. It is also used as a filler and extender for
a range of applications including paints and coatings, sealants, ceramics, and epoxy. The products produced as ground silica carry
the trademark Sil-Co-Sil™.

The grinding mills process material produced from the coarse-sand stream of Wet Processing Plant or from the Fine Sand Plant.
Dried whole grain sand is pulverized in ball mills using ceramic grinding media. The mill discharge is classified into size fractions
using air classifiers. The finished products are then moved into storage bins for bulk loading or packaging. The oversize grains are

rejected by the classifiers and return to the mill feed for re-grinding in a closed circuit.

14.1.4    ASTM Circuit
The ASTM Circuit produces U.S. Silica’s ASTM products. The Ottawa Operation has the distinct advantage of supplying the well-
known, highly respected original “Ottawa Silica” that is used for cement and abrasion testing under ASTM 20/30 and ASTM C109.
The Ottawa Operation remains the only supplier of fully ASTM-compliant sands in the world.

The ASTM Circuit takes material from the Sizing and Fine Sand Plant and passes it through several screening and blending
operations to produce silica sand meeting the rigid specifications required of ASTM products.

    JOHN T. BOYD COMPANY

14-4

14.2 Production
The Ottawa Operation’s LOM plan forecasts increased production from the processing plant until the nominal production capacity is
reached. Recent annual production results and forecasted production over the expected life of the operation is provided in Figure

14.2, below.

14.3    Conclusion

Based on our review, it is BOYD’s opinion that the processing methods and existing equipment at the plant will be sufficient for the
forecasted production of finished silica sand products.

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    JOHN T. BOYD COMPANY

15-1

15.0    MINE INFRASTRUCTURE

15.1    Overview

The infrastructure required for the ongoing operations is generally in place at the Ottawa Operation. Figure 3.1 (page 3-2) illustrates

the general layout of the infrastructure at the Ottawa Operation.

The surface facilities currently located at the operation are well constructed and have the necessary capacity/capabilities to support

the Ottawa Operation’s near-term operating plans. Operational preference may lead to the upgrading of some existing facilities if the

operation expands in the future.

BOYD is unaware of any reported interruptions, outages, shortages, or failures related to infrastructure requirements which have

materially affected the Ottawa Operation. Given the operation is well-established, we believe the risk of such events materially

affecting the estimates of silica sand reserves presented herein is low.

15.2    Transportation

The Ottawa Operation is serviced by a network of roads maintained by the local municipality, county, and state. These roads are

either paved or well-maintained graded roadways. Road access is available year-round.

The Illinois Railway is a former BNSF short line that handles rail car transfer for the processing plant. Empty rail cars are delivered

by the railway’s owner, OmniTrax, and loaded ones are moved to the CSX interchange located in the City of Ottawa, where they can

transfer to the mainline. Access to several other Class 1 railroads—BNSF, Union Pacific, and Norfolk Southern—is also available.

The BNSF has a connection with the Illinois Railway at Oswego, IL and Streator, IL. The Union Pacific and Norfolk Southern can be

accessed via truck transloading. U.S. Silica leases all its rail cars. Switching and other yard operations are performed by plant

personnel with the company’s Trackmobile Railcar Movers.

U.S. Silica also has access to several third-party owned barge terminals which are located on the north shore of the Illinois River.

The land upon which these terminals are located is owned by U.S. Silica.

15.3    Utilities

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15-2

Electric power for the processing plant is supplied by Ameren Illinois. It is delivered by an above-ground network of utility poles

running parallel with the CSX rail corridor and terminates at a substation located on the west end of the processing facility, directly

south of the Dry Product Plant. Power is then distributed to the facility by several underground powerlines and above ground poles.

The South Ottawa Pit is supplied with electricity by the Cornbelt Energy Corp.

Natural gas used by the processing plant is currently supplied by NiCor. The gas is delivered by several underground pipes running

parallel to the CSX rail line.

Water is used for both personnel consumption and for the mining/processing of the silica sand. Potable water is delivered to the

processing plant by the City of Ottawa’s public water system. A private well on site at the South Ottawa Pit is used for sanitary

needs of the employees there. Water for mining and processing operations is provided by a series of wells drilled at the South

Ottawa Pit site. In addition, U.S. Silica has a recycling system where water is recovered from processing and tailings disposal and

pumped back to the mine site for reuse. The water for industrial uses is transported by a series of pumps and HDPE pipelines,

either as a water/sand slurry mix, or recycled water.

15.4 Tailings Disposal

The mining and processing of silica sand at the Ottawa Operation creates a substantial amount of waste tailings. These tailings are

typically a mixture of clay, very fine sand, and other non-silica minerals. Tailings is typically disposed of in ponds (former mining pits)

where the solid materials settle to the bottom and water is recovered for reuse.

These tailings ponds are currently located directly to the east of the processing plant in the old mining pits. The existing tailing

ponds are designed to accommodate rejects generated during the next 5 to 10 years of production. Once mining has progressed to

the West Ottawa Pit, it is anticipated that the former South Ottawa Pit will be back filled with tailings.

    JOHN T. BOYD COMPANY

15-3

15.5 Other Structures

Several other buildings are located on the property, including:

• Office buildings that host operations, safety, financial, and administrative staff.
• Several support buildings for housing machinery and maintenance activities.
• A warehouse for material storage and product bagging
• Several product loadouts.
• Various pump structures and outbuildings.

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    JOHN T. BOYD COMPANY

16-1

16.0    MARKET STUDIES

16.1    Product Specifications

The Ottawa Operation is U.S. Silica’s largest “blended” operation, supplying various grades of silica sand to both the O&G and the

ISP markets. Their finished silica sand products are used in variety of industrial applications by a large customer base. Products

sold by the operation include:

•

•

•

40/70-mesh and 100-mesh silica sand for oil and gas proppants used in hydraulic fracturing (“fracking”). The availability of rail
and barge transportation allows the Ottawa Operation to serve distant markets, including the Bakken, Permian, and Marcellus
basins.

Fine-grain silica sand, called “F-Grade”, used in foundry casting.

200-mesh sized fine silica sand used as a cement additive for injecting into wells to bond steel casings to the rock.

• Bright, white very fine white silica powder called “Sil-Co-Sil” used for countertops, ceramics, fiberglass, and specialty glass.

• ASTM 20/30 and ASTM C109 compliant sand, called “Ottawa Silica”, that is used for cement and abrasion testing. The Ottawa

Operation remains the world’s only supplier of “Ottawa Silica”.

The Ottawa Operation’s long history, high quality sand, and robust transportation network allows it to transport product to both

industrial and oil and gas markets that would otherwise be uneconomical for similar deposits to enter.

16.2    Historical Sales

Recent historical sales data provided by U.S. Silica for the Ottawa Operation is summarized in Table 16.1, below.

    JOHN T. BOYD COMPANY

16-2

O&G demand, as well as whole silica demand generally, dropped in 2020 as compared to 2019 due to the COVID-19 pandemic.

However, recovery began in the fourth quarter of 2020 and continued throughout 2021 and 2022. In 2020, the average selling price

(ASP) was $36.91 per sold ton. In 2021, the ASP dropped to $34.47 per sold ton; however, the ASP rose to $42.37 per sold ton in

2022.

According to sales information provided by U.S. Silica for the Ottawa Operation:

• Sales of whole grain silica sand to the O&G segment account for approximately 60% of total sales. The ISP segment accounts

for nearly all of the remaining sales.

• Contract sales account for roughly 45% of total product sales.

•

The top-five customer by sales revenue account for approximately 15% of total sales.

BOYD is not aware of any material contracts for the sale of silica sand from the Ottawa Operation.

16.3    Market Outlook

Historically, the Ottawa Operation had been founded in 1900 as a supplier to the ISP markets—more specifically, the glass and

foundry industry which was in a state of expansion. As the market grew, the Ottawa Operation has also worked on diversifying to

other areas, such as ceramics, cement, and fiberglass.

In the last 20 years, the O&G industry in the United States has exploded in size in response to new technologies for horizontal

drilling and the fracking of tight hydrocarbon deposits. The proppants used to help free the oil and gas require a very fine silica sand

to prop open the cracks. The sand from the Ottawa Operation was found to be an excellent sand for this purpose due to its high

compressive strength and individual grain shapes. As demand for proppant sand grew, the Ottawa Operation underwent several

expansions to meet the needs of the O&G market.

Starting in the late 2010’s, to lower costs, oil and gas companies started to look for more locally sourced silica sand. Transportation

costs were attractive enough to spur the opening of many new silica sand mines (for example, U.S. Silica’s Crane and Lamesa

operations were opened in the Permian Basin in Texas for this reason). In 2020, due to COVID-19 and the collapse of oil and gas

prices, sales into the silica sand segment from the Ottawa Operation was significantly reduced. The industrial sand market was

affected

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16-3

as well, but not as greatly. Since late 2020, the oil and gas industry has become a dominant customer once again for the Ottawa

Operation. During this same period U.S. Silica has seen an increase in demand from its industrial customers

Having survived the challenging environment of 2019 and 2020, the Ottawa Operation should continue to prove viable into the

future notwithstanding a sustained and significant energy price collapse. Their low-cost mining scheme, advantaged transport to

select basins, and high-quality product help to create an advantage compared with other silica sand producers.

U.S. Silica expects sustained growth for the Ottawa Operation in both the O&G and ISP segments. Although local sources of

proppant sand have been developed and taken some demand away, it is expected that the Ottawa Operation’s higher quality

products will see increased, although uneven, demand in the O&G industry. The Ottawa Operation’s long history and excellent sand

quality should continue to drive growth in the ISP segment, especially with growth in demand for consumer goods.

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17-1

17.0    PERMITTING AND COMPLIANCE

17.1    Permitting

Numerous permits are required by federal, state, and municipal law for mining, processing, and related activities at the Ottawa

Operation. U.S. Silica reports that necessary permits to support current and near-term operations are in place or pending approval.

New permits or permit revisions may be necessary from time to time to facilitate future operations. Given sufficient time and

planning, U.S. Silica should be able to secure new permits, as required, to maintain its planned operations within the context of

current regulations.

A description of the salient permitting requirements for the Ottawa Operation follows.

The Illinois Department of Natural Resources (IDNR) requires a Surface Mining Permit for all operations that affect over 10 acres

per year by mining or remove more than 10 ft of overburden (soil on top of the rock or mineral being extracted). A Surface Mining

Permit application requires the operator to submit an operating plan that illustrates how the land will be affected by mining

operations, as well as a reclamation plan that describes how the mined land will be restored for future use. The mine reclamation

plan must be submitted for review to the LaSalle County Board. If the County Board requests, a public hearing will be scheduled by

the IDNR to receive comments on the proposed reclamation plan. The Ottawa Operation has current IDNR permits (Nos. 1862-12,

1743-15, 1776-17, and 1825-19). In support of these permits, a surety bond was issued to IDNR in the amount of $344,000 for

approximately 80 acres of surface mining reclamation.

U.S. Silica maintains a Spill Prevention, Controls and Countermeasure (SPCC) Plan at the Ottawa Operation to address

requirements of the federal Oil Pollution Prevention Regulations (40 CFR Part 112). The SPCC Plan establishes oil spill

preparedness, prevention, planning, response, and notification procedures per the federal regulations and addresses state-specific

oil spill reporting notification and response requirements as administered by the Illinois Emergency Management Agency (IEMA).

Construction of the slurry pipeline, which transports raw sand from the mine to the processing plant under the Illinois River, was

authorized by the US Army Corps of Engineers and IDNR as a Nationwide Permit 12 (CEMVR-OD-P-2006-53). In May of 2017,

U.S. Silica received approval from IDNR to replace the existing sand slurry

    JOHN T. BOYD COMPANY

17-2

pipeline within their easement under Statewide Permit No. 8 which authorizes the construction of underground pipeline and utility

crossings.

IDNR authorized a Mine Refuse Disposal Permit 1947-SP for the slurry refuse disposal area within an approximately 43-acre

inactive pit (“A Pit”) located at the North Ottawa site. The permit includes a description of proposed reclamation activities following

disposal activities.

U.S. Silica is permitted to discharge stormwater from the Mississippi Sands Mine under National Pollutant Discharge Elimination

System General Permit No. ILG840203. No mining has been conducted by U.S. Silica at the Mississippi Sands Mine as of the date

of this report.

Individual Permit No. IL0001325, as approved by the Illinois Environmental Protection Agency (ILEPA), authorizes discharge of

wastewater from the North and South Ottawa sites. Sampling and reporting requirements include three grab samples monthly

reported using the Discharge Monitoring Report system, quarterly visual monitoring, semi-annual monitoring and reporting of

metals, arsenic, cyanide and total phenols, and an annual inspection report.

Air emissions resulting from the processing plant at Ottawa are authorized under the ILEPA Clean Air Act Permit Program Permit

#95060046. Provisions of the permit include maintenance and calibration of monitoring devices and monthly opacity visible

emissions observations.

The Ottawa Operation is classified under RCRA Subtitle C as a Very Small Quantity Generator of Hazardous Waste (EPA ID

#ILD155166952), generating less than or equal to 100 kilograms per month of non-acute hazardous waste. Waste classifications

handled at the site include D001 Ignitable Waste, D002 Corrosive Waste, and D009 Mercury. U.S. Silica personnel maintain an

Illinois Radioactive Material License (#IL-01709-01) through the IEMA.

U.S. Silica maintains a LaSalle County Floodplain Development Permit #2014-12 for construction of an earthen berm within a

regulated Special Flood Hazard Area of the Illinois River watershed basin.

    JOHN T. BOYD COMPANY

17-3

17.2    Compliance

U.S. Silica reports having an extensive environmental management and compliance process designed to follow or to exceed

industry standards.

In their 2021 corporate sustainability report, U.S. Silica reports:

•

•

Increasing the use of renewable energy sources.

Improving the quality of local water by utilizing best-in-class tailings management techniques.

• Recycling or reusing tailings waste for land reclamation.

• Partnering with neighbors and local chapters of the North American Bluebird Society to provide safe nesting boxes, food, and

other habitat management measures to support the bluebird populations in and around the Ottawa Operation.

Mine safety is regulated by MSHA. MSHA inspects the facilities a minimum of twice yearly. U.S. Silica’s safety record compares

favorably with its regional peers.

Based on our review of information provided by U.S. Silica and available public information, it is BOYD’s opinion that the Ottawa

Operation’s record of compliance with applicable mining, water quality, and environmental regulations is generally typical for that of

the industry. BOYD is not aware of any regulatory violation or compliance issue which would materially impact the silica sand

reserve estimate.

17.3    Post-Mining Land Use and Reclamation

Disturbed areas at the Ottawa Operation must be reclaimed in accordance with approved reclamation and abandonment plans.

These plans are a condition of U.S. Silica’s operating permits and licenses and generally require:

Landscaping of berms and areas affected by berms.

•
• Regrading and landscaping of unconsolidated overburden piles and pit highwalls.
• Regrading and landscaping of disused roads.
• Natural flooding of the excavated pits for the creation of lakes.
• Removal of all equipment and product stockpiles.
• All hazardous wastes must be disposed of.

Mine site reclamation costs are funded from U.S. Silica’s Asset Retirement Obligations (ARO) account. Funding of the ARO account

is included in the Ottawa Operation’s operating costs discussed in Chapter 18 and included in the economic analysis

    JOHN T. BOYD COMPANY

17-4

presented in Chapter 19. ARO costs estimates are reviewed annually and current estimated at approximately $5.5 million for the

Ottawa Operation. As a matter of good mining practice, U.S. Silica seeks to conduct progressive reclamation throughout the

operation’s mining life to minimize risk and costs at closure.

17.4    Community Engagement

The Ottawa Operation has been a fixture in the Ottawa, Illinois community for over a century. U.S. Silica is one of the major

employers and economic contributors in the area. BOYD is unaware of any plans, negotiations, agreements with local individuals or

groups or commitments to ensure local procurement and hiring.

U.S. Silica’s corporate sustainability report outlines the components of its core community engagement initiatives. It's stated

priorities include increasing charitable contributions to organization that support the local community and actively seeking

opportunities for volunteering and community engagement.

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    JOHN T. BOYD COMPANY

18-1

18.0    CAPITAL AND OPERATING COSTS

18.1    Historical Financial Performance

Table 18.1 summarizes the past three years of financial data for the Ottawa Operation. We remind the reader that the COVID-19

pandemic caused severe economic, market, and other disruptions which began to affect U.S. Silica’s silica sand operations in the

second quarter of 2020.

Gross revenues include income from product sales and shipping.

Total cash costs of sales include operating costs (i.e., mining, ongoing reclamation, processing, product loadout, and other related

costs) in addition to selling, general, and administrative expenses.

Capital expenditures include maintenance (sustaining) expenses and discretionary spending on continuous improvement projects to

drive and maintain cost efficiencies.

Based on the financial data presented above:

• Average realization increased from $36.91 per ton sold in 2020 to $42.37 per ton sold in 2022.

•

Total cash cost of sales also increased from $29.48 per ton sold in 2020 to $32.85 per ton sold in 2022.

• EBITDA margin increased slightly from 20.1% in 2020 to 22.5% in 2022.

• Capital expenditures totaled almost $9.5 million over the three years, averaging $1.27 per ton sold.

    JOHN T. BOYD COMPANY

18-2

18.2    Estimated Costs

The production and unit cost estimates provided by U.S. Silica are based on actual past performance and their customary internal

budget review and approvals process. Operating volumes are well-defined and understood, as are mining and processing

productivities. As such, it is BOYD’s opinion that the production and financial projections are reasonable and are likely to be within ±

20% accuracy level.

This section contains forward-looking information related to capital and operating cost estimates for the Ottawa Operation.

There are inherent known and unknown risks and uncertainties associated with all mining operations. These risks, uncertainties,

and other factors are not quantifiable, but include or are not limited to, adverse general economic conditions, operating hazards,

inherent uncertainties in interpreting engineering and geologic data, fluctuations in commodity prices and prices for operational

services, government regulation and political risks, as well as other risks commonly associated with the mining industry.

18.2.1    Projected Capital Expenditures

The Ottawa Operation and related facilities are fully developed and should not require any near-term major capital investment to

maintain full commercial production. Historically, the timing and amount of capital expenditures has been largely discretionary and

within U.S. Silica’s control. Their budgetary allocations for sustaining and discretionary capital expenditures over the next three

years is provided in Table 18.2, below.

BOYD considers the near-term detailed capital expenditure schedule as presented by U.S. Silica to be reasonable and
representative of the capital necessary to operate the Ottawa Operation.

    JOHN T. BOYD COMPANY

18-3

After 2025, capital expenditures are projected to increase 3% per year from 2025’s level until the end of operation’s life. As the
Ottawa Operation is in a steady state of production, the projected capital expenditures are considered reasonable and expected.

18.2.2    Projected Operating Costs
Operating cost estimates were developed based on recent actual costs and considering specific operational activity levels and cost
drivers. The estimates consider current and expected labor headcount and salaries, major consumables and unit prices, power
costs, and equipment and maintenance costs. The total operating cost estimate includes all site costs related to mining, processing,
and general and administrative activities.

In the near-term, U.S. Silica expects their unit operating costs to stay relatively consistent (on an uninflated basis). As such, the

projected total cash cost of sales over the life of the mine is $32.85 per ton sold. As the operation is in a steady state, BOYD

considers the future operating cost estimates to be reasonable and appropriate.

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    JOHN T. BOYD COMPANY

19-1

19.0    ECONOMIC ANALYSIS

19.1    Approach

The economic analysis presented in this chapter was made for the purposes of confirming the commercial viability of the Ottawa

Operation’s reported silica sand reserves and not for the purposes of valuing U.S. Silica, the Ottawa Operation, or its assets. The

economic analysis contains forward-looking information related to the projected operating and financial performance of the Ottawa

Operation and therefore involves inherent known and unknown risks and uncertainties, some of which may be outside of U.S.

Silica’s control. U.S. Silica, as with all mining companies, actively evaluates, changes, and modifies business and operating plans in

response to various factors that may affect operational and/or financial results. Actual results, production levels, operating

expenses, sales realizations, and all other modifying factors could vary significantly from the assumptions and estimates provided in

this analysis. Risk is subjective, as such, BOYD recommends that each reader should evaluate the project based on their own

investment criteria.

The financial model used for the purposes of the economic analysis has been prepared in-house by U.S. Silica as part of their

annual budgeting process. The model forecasts future free cash flow from silica sand production and sales over the life cycle of the

Ottawa Operation using the annual forecasts of production, sales revenues, and operating and capital costs discussed earlier in this

report. A DCF analysis, in which future free cash flows are discounted to present value, is used to derive a NPV for the silica sand

reserves. Use of DCF-NPV analysis is a standard method within the mining industry to assess the economic value of a project after

allowing for the cost of capital invested.

The financial evaluation of the Ottawa Operation has been undertaken on a simplified after-tax basis and does not reflect U.S.

Silica’s corporate tax structure. NPV is calculated using an after-tax discount rate of 12.5% (NPV ). Cash flows were assumed to

12.5

occur in the middle of each year and are discounted to mid-year 2022. Cost estimates and other inputs to the cash flow model for

the project have been prepared using constant 2022 money terms, i.e., without provision for inflation. Internal rate of return and

project payback were not calculated, as there was no initial investment (sunk costs) considered in the financial model provided

herein.

JOHN T. BOYD COMPANY

19-2

A suite of sensitivities was calculated to evaluate the effect of the main drivers of economic performance, including variations in

sales prices, operating costs, and capital costs.

BOYD has reviewed the financial model and its inputs in detail. It is our opinion that the financial model provides a reasonable and

accurate reflection of the Ottawa Operation’s expected economic performance based on the assumptions and information available

at the time of our review.

19.2    Assumptions and Limitations

Cash flow projections for the Ottawa Operation have been generated from the annual forecasts of production, sales revenues, and

operating and capital costs discussed earlier in this report. A summary of the key assumptions and limitations is provided below:

• Sales volumes of finished silica sand are expected to increase 3% per annum (limited by processing plant capacity of 3.29

million product tons per year) while maintaining a consistent product mix.

• ROM production requirements are based an expected processing yield of 86.5% (the historic average) and are also projected to
increase 3% per annum until plant capacity is reached. Forecasted ROM production is at or below the capacity of the existing
mining equipment and related infrastructure.

•

Forecasted revenues are based on sales of various grades of finished silica sand with a weighted-average sales price of $42.37
per ton.

• Capital and operating costs are discussed in Chapter 18. Capital expenditures are derived from budgetary allocations for the

first three years of the forecast and escalated thereafter at 3% per annum. Unit operating costs are expected to remain relatively
constant over the life of the operation at $32.85 per sold ton.

•

Taxes are based on:
− Federal Business Income Tax rate of 21%.
− Illinois Corporate Income and Replacement Tax rate of 9.5%.

• Buildup of net working capital is equal to 25% of positive cash (operating) margins.

• Depreciation and amortization expenses are estimated as the average of the proceeding three years.

• No asset recovery/salvage values were included in the valuation.

19.3    Financial Model Results

JOHN T. BOYD COMPANY

19-3

Estimated LOM pre-tax and after-tax cash flows for silica sand production from the Ottawa Operation are presented in Table 19.1,

on the following page.

JOHN T. BOYD COMPANY

19-3

JOHN T. BOYD COMPANY

Table 19.2, below, provides a summary of the estimated remaining life of mine financial results for the Ottawa Operation.

19-4

DCF-NPV on a pre-tax and after-tax basis, using discount rates of 10%, 12.5% (the base case), and 15%, were calculated utilizing

the projected cash flows. Table 19.3 summarizes the results of the pre-tax and after-tax DCF-NPV analyses:

As shown, the pre-tax DCF-NPV ranges from approximately $190.7 million to $262 million. The after-tax DCF-NPV ranges from

approximately $142.1 million to $195 million.

The economic analysis confirms that the Ottawa Operation generates positive pre- and after-tax financial results and a real NPV

12.5

of $164.9 million. As such, it is BOYD’s

JOHN T. BOYD COMPANY

19-5

opinion that the Ottawa Operation’s silica sand reserves have demonstrated economic viability.

19.4    Sensitivity Analysis

Table 19.4, below, shows the sensitivity of the project after-tax for a cash flow discounted at 12.5% (NPV ) to a variation over a

12.5

range of 20% above and below the base case in: (1) average selling prices and (2) operating costs.

As might be expected, the project is most sensitive to changes in product pricing and operating costs. The Ottawa Operation

generates negative value only if costs are increased substantially and selling prices are reduced dramatically.

The project is less sensitive to capital costs. There is little to no impact varying the capital costs from 70% to 130% of the base

case.

This analysis demonstrates the project value to be relatively robust, with positive NPVs reported across the range of values

assessed.

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JOHN T. BOYD COMPANY

20-1

20.0    ADJACENT PROPERTIES

There is no information used in this report that has been sourced from adjacent properties. There are no other active silica sand

mines in the immediate vicinity of the Ottawa Operation.

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    JOHN T. BOYD COMPANY

21-1

21.0    OTHER RELEVANT DATA AND INFORMATION

BOYD is not aware of any additional information which would materially impact the silica sand reserve estimates reported herein.

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    JOHN T. BOYD COMPANY

22-1

22.0    INTERPRETATION AND CONCLUSIONS

22.1    Audit Findings

BOYD’s independent technical assessment was conducted in accordance with S-K 1300 and concludes:

• Sufficient data have been obtained through site exploration and sampling programs and mining operations to support the

geological interpretations of the sandstone deposit underlying the controlled property of the Ottawa Operation. The data are of
sufficient quantity and reliability to reasonably support the silica sand resource and reserve estimates presented in this report.

• BOYD is of the opinion that our data verification efforts: (1) adequately support confirm the reasonableness of geologic

interpretations, resource estimation criteria, and economic assumptions, (2) and therefore support the use of the data in silica
sand resource/reserve estimation.

•

•

•

The 78.9 million saleable product tons of silica sand reserves (as of December 31, 2022) identified on the property are
reasonably and appropriately supported by technical studies, which consider expected geologic conditions, planned mining and
processing operations, forecasted product revenues, and operating and capital cost estimates. As such, BOYD is of the opinion
that there are reasonable expectations that the stated silica sand reserves for the Ottawa Operations are technically,
economically, and legally extractable as of December 31, 2022.

In addition to the reported reserves, U.S. Silica controls approximately 88,000 in-place tons of inferred silica sand resources at
the Ottawa Operation. It is BOYD’s opinion that the stated silica sand resources have been reported using economic and mining
assumptions to support the reasonable potential for eventual economic extraction.

There is no other relevant information material to the Ottawa Operation that is necessary to make this technical report summary
not misleading.

22.2    Significant Risks and Uncertainties

As a mining operation with a lengthy operating history, the purpose of U.S. Silica’s periodic mine planning exercises is to: (1) collect

and analyze sufficient data to reduce or to eliminate risk in the technical components of the project, and to, (2) refine economic

projections based on current data. There is a high degree of certainty for this project under the current and foreseeable operating

environment. A general assessment of risk is presented in the relevant sections of this report.

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    JOHN T. BOYD COMPANY

23-1

23.0    RECOMMENDATIONS

Based on the scope of our assignment, BOYD has no recommendations regarding the Ottawa Operation. It is our understanding

that U.S. Silica continuously reviews and improves operating practices as a matter of course.

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    JOHN T. BOYD COMPANY

24-1

A list of supporting information is provided in Section 2.4. Additional references are cited as footnotes in the report as required.

24.0    REFERENCES

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    JOHN T. BOYD COMPANY

25-1

25.0    RELIANCE ON INFORMATION PROVIDED BY REGISTRANT

In the preparation of this report, BOYD has relied, exclusively and without independent verification, upon information furnished by

U.S. Silica as presented in Table 25.1, below.

BOYD exercised due care in reviewing the information provided by U.S. Silica within the scope of our expertise and experience

(which is in technical and financial mining issues) and concluded the data are reasonable and appropriate considering the status of

the subject properties and the purpose for which this report was prepared. We have no reason to believe that any material facts

have been withheld or misstated, or that further analysis may reveal additional material information. However, the accuracy of the

results and conclusions of this report are reliant on the accuracy of the information provided by U.S. Silica.

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    JOHN T. BOYD COMPANY

TECHNICAL REPORT SUMMARY

DIATOMACEOUS EARTH RESOURCES AND RESERVES

COLADO OPERATION

Pershing County, Nevada

Prepared For

U.S. SILICA COMPANY

Katy, Texas

By

John T. Boyd Company

Mining and Geological Consultants

Pittsburgh, Pennsylvania

Report No. 3076.017

FEBRUARY 2023

 John T. Boyd Company

    Mining and Geological Consultants

February 22, 2023

    
    
 John T. Boyd Company

    Mining and Geological Consultants

File: 3076.017

U.S. Silica Company
24275 Katy Freeway, Suite 600
Katy, TX 77494-7271

Attention:    Mr. Terry Lackey

    Mining Director

Subject:    Technical Report Summary
        Diatomaceous Earth Resources and Reserves
        Colado Operation
        Pershing County, Nevada

Ladies and Gentlemen:

The John T. Boyd Company (BOYD) was retained by U.S. Silica Company (U.S. Silica) to complete an independent technical
assessment of the diatomaceous earth (DE) resource and reserve estimates for the Colado Operation as of December 31, 2022.

This technical report summary: (1) summarizes material technical and geoscientific information for the subject mining property,
(2) provides the conclusions of our technical assessment, and (3) provides a statement of DE resources and reserves for the
Colado Operation.

Respectfully submitted,

JOHN T. BOYD COMPANY
By:

John T. Boyd II
President and CEO

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    TABLE OF CONTENTS

    Page
LETTER OF TRANSMITTAL

TABLE OF CONTENTS

GLOSSARY AND ABBREVIATIONS

1.0    EXECUTIVE SUMMARY     1-1
    1.1    Introduction     1-1
    1.2    Property Description     1-1
    1.3    Geology     1-3
    1.4    Exploration     1-4
    1.5    Diatomaceous Earth Resources and Reserves     1-4
    1.6    Operations     1-5
        1.6.1    Mining     1-5
        1.6.2    Processing     1-6
        1.6.3    Other Infrastructure     1-6
    1.7    Financial Analysis     1-6
        1.7.1    Market Analysis     1-6
        1.7.2    Capital and Operating Cost Estimates     1-7
        1.7.3    Economic Analysis     1-8
    1.8    Permitting and Compliance     1-9
    1.9    Conclusions     1-10

2.0    INTRODUCTION     2-1
    2.1    Registrant     2-1
    2.2    Terms of Reference and Purpose     2-1
    2.3    Expert Qualifications     2-2
    2.4    Principal Sources of Information     2-3
    2.5    Personal Inspections     2-3
    2.6    Report Version     2-4
    2.7    Units of Measure     2-4

3.0    PROPERTY DESCRIPTION     3-1
    3.1    Location     3-1
    3.2    Property Rights    3-1
    3.3    Encumbrances    3-5
        3.3.1 Fees and Royalties    3-5
        3.3.2 Permitting Requirements    3-5
        3.3.3 Mining Restrictions    3-5
        3.3.4 Other Significant Factors or Risks    3-6

4.0    PHYSIOGRAPHY, ACCESSIBILITY, AND INFRASTRUCTURE     4-1
    4.1    Topography, Elevation, and Vegetation     4-1
    4.2    Accessibility     4-1
    4.3    Climate    4-1
    4.4    Infrastructure Availability and Sources     4-2

JOHN T. BOYD COMPANY

        
    
    TABLE OF CONTENTS    - Continued  

    Page

5.0    HISTORY     5-1
    5.1    Reserve Acquisition     5-1
    5.2    Exploration and Development     5-1

6.0    GEOLOGICAL SETTING, MINERALIZATION, AND DEPOSIT     6-1
    6.1    Regional Geology     6-1
    6.2    Local Geology     6-1
        6.2.1    Stratigraphy     6-1
        6.2.2    Structural Geology     6-3
    6.3    Property Geology     6-3
    6.4    Diatomaceous Earth    6-4

7.0    EXPLORATION DATA     7-1
    7.1    Background     7-1
    7.2    Exploration Procedures     7-1
        7.2.1    Geologic Mapping     7-1
        7.2.2    Drilling    7-1
        7.2.3    Sampling Procedures    7-2
        7.2.4    Ore Testing     7-2
        7.2.5    Other Exploration Methods    7-3
    7.3    Exploration Results     7-3
        7.3.1    Summary of Exploration     7-3
        7.3.2    Ore Quality    7-5
    7.4    Data Verification     7-5
    7.5    Adequacy of Exploration and Sampling    7-5

8.0    SAMPLE PREPARATION, ANALYSIS, AND SECURITY     8-1

9.0    DATA VERIFICATION     9-1

10.0    MINERAL PROCESSING AND METALLURGICAL TESTING     10-1

11.0    DIATOMACEOUS EARTH RESOURCE ESTIMATE     11-1
    11.1    Applicable Standards and Definitions     11-1
    11.2    Diatomaceous Earth Resources     11-2
        11.2.1     Methodology     11-2
        11.2.2     Estimation Criteria     11-2
        11.2.3     Classification     11-3
        11.2.4     Diatomaceous Earth Resource Estimate     11-4
        11.2.5     Validation     11-5

12.0    DIATOMACEOUS EARTH RESERVE ESTIMATE     12-1
    12.1    Applicable Standards and Definitions     12-1
    12.2    Diatomaceous Earth Reserves     12-2
        12.2.1     Methodology    12-2
        12.2.2     Classification    12-3
        12.2.3     Diatomaceous Earth Reserve Estimate     12-3

JOHN T. BOYD COMPANY

    
    
    
    TABLE OF CONTENTS    - Continued  

    Page

        12.2.4     Reconciliation with Previous Estimates     12-5

13.0    MINING METHODS     13-1
    13.1    Mining Operations    13-1
    13.2    Mine Equipment and Staffing     13-3
        13.2.1    Mine Equipment     13-3
        13.2.2    Staffing     13-4
    13.3    Engineering and Planning     13-4
    13.4    Mining Sequence and Production     13-5

14.0    PROCESSING OPERATIONS     14-1
    14.1    Overview     14-1
        14.1.1 Colado Processing Plant    14-1
    14.2    Production     14-3
    14.3    Conclusion     14-3

15.0    MINE INFRASTRUCTURE     15-1
    15.1    Overview     15-1
    15.2    Transportation     15-1
    15.3    Utilities    15-1
    15.4    Tailings Disposal    15-2
    15.5    Other Structures    15-2

16.0    MARKET STUDIES     16-1
    16.1    Product Specifications     16-1
    16.2    Historical Sales     16-1
    16.3    Market Outlook     16-2

17.0    PERMITTING AND COMPLIANCE     17-1
    17.1    Permitting     17-1
    17.2    Compliance     17-2
    17.3    Post-Mining Land Use and Reclamation    17-3
    17.4    Community Engagement    17-3

18.0    CAPITAL AND OPERATING COSTS     18-1
    18.1    Historical Financial Performance     18-1
    18.2    Estimated Costs     18-2
        18.2.1 Projected Capital Expenditures     18-2
        18.2.2 Projected Operating Costs    18-3

19.0    ECONOMIC ANALYSIS     19-1
    19.1    Approach     19-1
    19.2    Assumptions and Limitations     19-2
    19.3    Financial Model Results    19-2
    19.4    Sensitivity Analysis    19-5

20.0    ADJACENT PROPERTIES     20-1

JOHN T. BOYD COMPANY

    
    TABLE OF CONTENTS    - Continued  

    Page

21.0    OTHER RELEVANT DATA AND INFORMATION     21-1

22.0    INTERPRETATION AND CONCLUSIONS     22-1
    22.1    Audit Findings     22-1
    22.2    Significant Risks and Uncertainties     22-1

23.0    RECOMMENDATIONS     23-1

24.0    REFERENCES     24-1

25.0    RELIANCE ON INFORMATION PROVIDED BY REGISTRANT     25-1

JOHN T. BOYD COMPANY

    TABLE OF CONTENTS    - Continued  

    Page

List of Tables
1.1    Colado Operation Diatomaceous Earth Resources (as of December
    31, 2022)    1-4
1.2    Colado Operation Diatomaceous Earth Reserves (as of December
    31, 2022)    1-5
1.3    Financial Results    1-8
1.4    DCF-NPV Analysis    1-9
3.1    Property Control Summary     3-1
7.1    Drill Hole Summary Bay Area    7-3
11.1    Diatomaceous Earth Resource Classification Criteria    11-4
11.2    Colado Operation Diatomaceous Earth Resources (as of December
    31, 2022)    11-4
12.1    Colado Operation Diatomaceous Earth Reserves (as of December
    31, 2022)    12-4
13.1    Colado Operation Mining Areas    13-1
13.2    Employees by Classification    13-4
13.3    Colado Operation Generalized Mining Sequence    13-5
16.1    Historical Sales Data     16-1
18.1    Historical Financials    18-1
18.2    Projected Capital Costs    18-2
19.1    Annual Production and Cash Flow Forecast Colado Operation     19-3
19.2    Financial Results    19-4
19.3    DCF-NPV Analysis     19-4
19.4    After-Tax NPV  Sensitivity Analysis ($ millions)     19-5
25.1    Information Relied Upon from Registrant    25-1

12.5

JOHN T. BOYD COMPANY

    TABLE OF CONTENTS    - Continued  

    Page

List of Figures
1.1    General Location Map Showing Colado Operation    1-2
3.1    Map Showing Colado Mine    3-3
3.2    Map Showing Colado Processing Plant    3-4
6.1    Generalized Stratigraphic Chart, Surface and Near-Surface Geologic
    Units, Pershing County, Nevada    6-2
6.2    Map Showing Cross Section Locations    6-5
6.3    Cross Section A-A’ Horseshoe Basin Central    6-6
6.4    Cross Section B-B’ Horseshoe Basin East    6-7
6.5    Cross Section C-C’ Liberty Basin    6-8
6.6    Cross Section D-D’ Antelope Basin    6-9
7.1    Map Showing Drill Hole Locations    7-4
12.1    Relationship Between Mineral Resources and Mineral Reserves    12-2
13.1    Loading Operations at the Colado Operation    13-2
13.2    Recent Historical and LOM Forecasted Mining Production    13-5
13.3    Map Showing Life-of Mine Plan    13-6
14.1    Simplified Flow Sheet    14-2
14.2    Recent Historical and LOM Forecasted Processing Plant Production    14-3

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000
$
%
AMSL
ARO
ASP
ASTM
BLM
BOYD
CAGR
CapEx
Constant Dollar

DCF
DE
Diatomaceous Earth

Diatomaceous Earth
Reserve

GLOSSARY OF ABBREVIATIONS AND DEFINITIONS

:
:
:
:
:
:
:
:
:
:
:
:

:
:
:

:

Thousand(s)
US dollar(s)
Percent or percentage
Above mean sea level
Asset Retirement Obligation(s)
Average Selling Price
ASTM International (formerly American Society for Testing and Materials)
Bureau of Land Management. A division of the U.S. Department of the Interior.
John T. Boyd Company
Compound Annual Growth Rate
Capital Expenditures
A monetary measure that is not influenced by inflation and used to compare time periods.
Sometimes referred to as “real dollars”.
Discounted Cash Flow
Diatomaceous Earth
Diatomaceous earth, commonly known as diatomite, is a naturally occurring sedimentary rock
that is a result of the accumulation of skeletal remains of diatoms, which are microscopic single-
celled aquatic algae.
Diatomaceous earth reserve is an estimate of tonnage and grade or quality of indicated and
measured diatomaceous earth resources that, in the opinion of the qualified person, can be the
basis of an economically viable project. More specifically, it is the economically mineable part of a
measured or indicated diatomaceous earth resource, which includes diluting materials and
allowances for losses that may occur when the material is mined or extracted.

JOHN T. BOYD COMPANY

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GLOSSARY OF ABBREVIATIONS AND DEFINITIONS - Continued

Diatomaceous Earth
Resource

Discount Rate

EBIT
EBITDA
EP Minerals
ft
Indicated Diatomaceous
Earth Resource

Inferred Diatomaceous
Earth Resource

IRR
ISO

:

:

:
:
:
:
:

:

:

Diatomaceous earth resource is a concentration or occurrence of diatomaceous earth material of
economic interest in or on the Earth's crust in such form, grade or quality, and quantity that there
are reasonable prospects for economic extraction. A diatomaceous earth resource is a
reasonable estimate of mineralization, taking into account relevant factors such as cut-off grade,
likely mining dimensions, location or continuity, that, with the assumed and justifiable technical
and economic conditions, is likely to, in whole or in part, become economically extractable. It is
not merely an inventory of all mineralization drilled or sampled.
A rate of return used to discount future cash flows based on the return investors expect to receive
from their investment.
Earnings before interest and taxes
Earnings before interest, taxes, depreciation, and amortization
EP Minerals, LLC., a wholly owned subsidiary of U.S. Silica.
Foot/feet
That part of a diatomaceous earth resource for which quantity and quality are estimated based on
adequate geological evidence and sampling. The level of geological certainty associated with an
indicated diatomaceous earth resource is sufficient to allow a qualified person to apply modifying
factors in sufficient detail to support mine planning and evaluation of the economic viability of the
deposit. Because an indicated diatomaceous earth resource has a lower level of confidence than
the level of confidence of a measured diatomaceous earth resource, an indicated diatomaceous
earth resource may only be converted to a probable diatomaceous earth reserve.
That part of a diatomaceous earth resource for which quantity and quality are estimated based on
limited geological evidence and sampling. The level of geological uncertainty associated with an
inferred diatomaceous earth resource is too high to apply relevant technical and economic factors
likely to influence the prospects of economic extraction in a manner useful for evaluation of
economic viability. Because an inferred diatomaceous earth resource has the lowest level of
geological confidence of all diatomaceous earth resources, which prevents the application of the
modifying factors in a manner useful for evaluation of economic viability, an inferred
diatomaceous earth resource may not be considered when assessing the economic viability of a
mining project, and may not be converted to a diatomaceous earth reserve.
Internal rate-of-return
International Organization for Standardization

JOHN T. BOYD COMPANY

    
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GLOSSARY OF ABBREVIATIONS AND DEFINITIONS - Continued

lb
LOM
Measured Diatomaceous
Earth Resource

Mesh
Mineral Reserve
Mineral Resource
Modifying Factors

MSHA
NDEP
NPV

:
:
:

:
:
:

:
:
:

Pound
Life-of-Mine
That part of a diatomaceous earth resource for which quantity and quality are estimated based on
conclusive geological evidence and sampling. The level of geological certainty associated with a
measured diatomaceous earth resource is sufficient to allow a qualified person to apply modifying
factors, as defined herein, in sufficient detail to support detailed mine planning and final
evaluation of the economic viability of the deposit. Because a measured diatomaceous earth
resource has a higher level of confidence than the level of confidence of either an indicated
diatomaceous earth resource or an inferred diatomaceous earth resource, a measured
diatomaceous earth resource may be converted to a proven diatomaceous earth reserve or to a
probable diatomaceous earth reserve
A measurement of particle size often used in determining the size distribution of granular material.
See “Diatomaceous Earth Reserve”
See “Diatomaceous Earth Resource”
The factors that a qualified person must apply to indicated and measured diatomaceous earth
resources and then evaluate to establish the economic viability of diatomaceous earth reserves. A
qualified person must apply and evaluate modifying factors to convert measured and indicated
diatomaceous earth resources to proven and probable diatomaceous earth reserves. These
factors include but are not restricted to: mining; processing; infrastructure; economic; marketing;
legal; environmental compliance; plans, negotiations, or agreements with local individuals or
groups; and governmental factors. The number, type and specific characteristics of the modifying
factors applied will necessarily be a function of and depend upon the mineral, mine, property, or
project.
Mine Safety and Health Administration. A division of the U.S. Department of Labor.
Nevada Division of Environmental Protection
Net Present Value

JOHN T. BOYD COMPANY

    
    4

Probable Diatomaceous
Earth Reserve

Production Stage Property
Proven Diatomaceous
Earth Reserve
PSI
QP
Qualified Person

:

:
:

:
:
:

GLOSSARY OF ABBREVIATIONS AND DEFINITIONS - Continued

The economically mineable part of an indicated and, in some cases, a measured diatomaceous
earth resource.

A property with material extraction of diatomaceous earth reserves.
The economically mineable part of a measured diatomaceous earth resource which can only
result from conversion of a measured diatomaceous earth resource.
Pounds per square inch
Qualified Person
An individual who is:

1. A mineral industry professional with at least five years of relevant experience in the type of

mineralization and type of deposit under consideration and in the specific type of activity that
person is undertaking on behalf of the registrant; and

2. An eligible member or licensee in good standing of a recognized professional organization at
the time the technical report is prepared. For an organization to be a recognized professional
organization, it must:

a. Be either:

i. An organization recognized within the mining industry as a reputable professional

association; or

ii.A board authorized by U.S. federal, state, or foreign statute to regulate professionals

in the mining, geoscience, or related field;

b. Admit eligible members primarily based on their academic qualifications and experience;
c. Establish and require compliance with professional standards of competence and ethics;
d. Require or encourage continuing professional development;
e. Have and apply disciplinary powers, including the power to suspend or expel a member

regardless of where the member practices or resides; and

f. Provide a public list of members in good standing.

ROM

SEC

:

:

Run-of-Mine. The processing feed material, including diatomaceous earth and any inseparable
waste, excavated from the mine.
U.S. Securities and Exchange Commission

JOHN T. BOYD COMPANY

    
 
 
    5

S-K 1300

SPCC
Ton
UP
USGS
U.S. Silica

GLOSSARY OF ABBREVIATIONS AND DEFINITIONS - Continued

:

:
:
:
:
:

Subpart 1300 and Item 601(b)(96) of the U.S. Securities and Exchange Commission’s Regulation
S-K
Spill Prevention, Controls and Countermeasure
Short Ton. A unit of weight equal to 2,000 pounds
Union Pacific
U.S. Geological Survey
U.S. Silica Company, its parent company (U.S. Silica Holdings, Inc.) and its consolidated
subsidiaries as a combined entity.

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1.0    EXECUTIVE SUMMARY

1.1    Introduction

U.S. Silica’s Colado Operation is an active surface DE mining and processing operation that has been in existence for over 65

years.

BOYD prepared this technical report summary for U.S. Silica in support of their disclosure of DE resources and reserves for the

Colado Operation in accordance with Subpart 1300 and Item 601(b)(96) of the SEC's Regulation S-K (S-K 1300). The purpose of

this report is threefold: (1) to summarize material technical and geoscientific information for the subject mining property, (2) to

provide the conclusions of our technical assessment, and (3) to provide a statement of DE resources and/or reserves for the Colado

Operation.

Information used in our assessment was obtained from: (1) files provided by U.S. Silica, (2) discussions with U.S. Silica personnel,

(3) records on file with regulatory agencies, (4) public sources, and (5) nonconfidential information in BOYD’s possession.

Unless otherwise noted, the effective date of the information, including estimates of DE resources and reserves, is December 31,
2022.

Weights and measurements are expressed in the US customary measurement system throughout this report.

1.2    Property Description

Located in Pershing County, Nevada, U.S. Silica’s Colado Operation comprises a surface mining operation (the “Colado Mine”) and

a processing plant (the “Colado Processing Plant”). The mine and plant are in Pershing County, Nevada, approximately 80 miles

northeast of the City of Reno. The general location of the Colado Operation is provided in Figure 1.1, following this page.

JOHN T. BOYD COMPANY

1-2

1-3

U.S. Silica holds surface and/or mineral rights to approximately 9,526 acres across the two sites that comprise the Colado

Operation. The Colado Mine property comprises ±8,993 acres of private and federal lands leased from the Franco-Nevada U.S.

Corporation (Franco-Nevada) and the U.S. Department of the Interior’s Bureau of Land Management (BLM), respectively. The

Colado Processing Plant property encompasses ±533 acres owned in fee by U.S. Silica or leased from the BLM. BOYD is not

aware of any encumbrances, litigation, or orders which would hinder continued development of the property.

1.3    Geology

Exploration and mining activities have identified several near-surface DE deposits on the Colado Mine property. DE, commonly

known as diatomite, is a naturally occurring sedimentary rock that is a result of the accumulation of skeletal remains of diatoms,

which are microscopic single-celled aquatic algae. Diatom skeletons are composed primarily of amorphous silica (non-crystalline

SiO ). The cylindrical shape and high pore volume of these diatom skeletons provide high mechanical strength, natural filtration, and

2

absorption capabilities.

The mineable DE on the Colado property is typically observed as consisting of between one to four beds (varies by pit) separated

by friable tuffaceous (compacted volcanic ash) units. The DE beds are generally white or light pink in color and tend to be very

clean, while the interbedded tuffaceous units are generally gray in color. The contrast in bed coloring makes visual selection during

mining relatively easy.

Welded and lithic tuffs directly overly the DE beds, with Miocene to Pliocene (Tertiary) age basalt flows forming a weathering-

resistant capping unit, which has helped preserve the underlying strata from being eroded.

Structure within the immediate area is considered to be relatively simple when compared to other uplifted blocks, as low dip angles

(generally less than 10 degrees) are noted in most of the DE beds being mined.

Several high-angle displacement faults are present at the Colado Mine, however throughout the typical course of mining

(overburden removal and benching into deeper DE beds), these areas are well exposed, allowing modified mining operations when

required.

JOHN T. BOYD COMPANY

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1.4    Exploration
The Colado Mine has been extensively explored and mined since the late 1950s. Throughout various exploration campaigns, the

subject DE deposits have been identified and delineated through geologic mapping, outcrop sampling, trenching, geophysical
surveys, and extensive exploration drilling. BOYD was provided source records (drilling logs, testing results, and core photographs),
summary reports, and/or databases compiling the results 1,153 drill holes located in and around the Colado Mine property. These
data were utilized to delineate the lateral extent, thickness, and quality of the remaining DE resources and reserves at the Colado

Operation.

BOYD’s audit indicates that in general: (1) U.S. Silica has performed extensive drilling and sampling work on the subject property,
(2) the work completed has been done by competent personnel, and (3) the amount of data available combined with extensive
knowledge of and historic production from subject DE beds are sufficient to confirm the thickness, lateral extents, and quality

characteristics of the Colado Operation’s DE resources and reserves.

1.5    Diatomaceous Earth Resources and Reserves
As shown in Table 1.1, below, U.S. Silica owns approximately 689,000 in place tons of inferred DE resources, exclusive of DE
reserves, at the Colado Operation, as of December 31, 2022.

While these “additional” DE resources have not been included in the Colado Operation’s life-of-mine (LOM) plan, they are

considered to have prospects for eventual economic extraction by virtue of their similarity—in terms of demonstrated extraction
methods and expected finished product qualities—to those converted to DE reserves.

JOHN T. BOYD COMPANY

U.S. Silica’s estimated surface mineable DE reserves for the Colado Operation total 3.7 million saleable product tons remaining as
of December 31, 2022. The DE reserves are fully controlled by U.S. Silica and are summarized in Table 1.2, below.

1-5

The Colado Operation has a well-established history of mining, processing, and selling DE products into various markets. BOYD

has concluded that sufficient studies have been undertaken to enable the DE resources to be converted to DE reserves based on

proposed operating methods and forecasted costs and revenues.

1.6    Operations

1.6.1    Mining

The DE mining horizons at the Colado Mine are relatively shallow, quite thick, and are moderately dipping. These characteristics
favor conventional surface mining techniques using excavators and trucks. Mining occurs on benches, in a stair-like fashion, to

remove the overburden waste material and expose the DE beds.

Excavation of the DE beds occurs from late spring until early fall, a period of roughly 200 days, before wet winter weather impedes

moisture control in the ROM stockpiles. During the winter months, the removal of overburden and other support activities continues

as access to the site is typically available year-round. The Colado Mine maintains a stockpile of approximately 600,000 cubic yards

at the mine site to meet the demands of the processing plant. U.S. Silica’s LOM Plan requires mining 141,000 to 196,000 ROM tons

annually, well within the capacity of the current mining fleet.

BOYD reviewed the LOM plans for U.S. Silica’s Colado Operation to determine whether the plans: (1) utilize generally accepted

engineering practices, and (2) align with historical and industry norms. Based on our assessment, it is BOYD’s opinion that the

forecasted production levels for the Colado Operation are reasonable, logical, and

JOHN T. BOYD COMPANY

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consistent with typical surface mining practices and historical results achieved by U.S. Silica.

1.6.2    Processing

The production of finished DE products begins when the plant receives raw DE from the mine by truck. From this raw feed material,

numerous products are generated through various processing methods, including kiln drying, milling, and sizing.

Since its construction in the late 1950s, the Colado Processing Plant has been upgraded and expanded several times as needed to

meet specific market demands. The plants currently run 24 hours a day, nearly 300 days a year, with a nominal capacity of 162,000

tons of finished DE products per year.

Based on our review, it is BOYD’s opinion that the processing methods and existing equipment at the plant will be sufficient for the

forecasted production levels over the life of the operation.

1.6.3    Other Infrastructure

The Colado Mine is remote with little installed mine-related infrastructure. The mine site is accessible by private and state roads.

Energy for the mine site is provided primarily by diesel powered equipment. Fuel and water is trucked to the site by local suppliers

and stored in tanks.

The Colado Processing Plant has been operating in its present location for over 60 years and is supplied with reliable and sufficient

power and natural gas from regional utility companies. Water for the Colado plant comes from municipal sources. Waste disposal

and handling capacity and capability is sufficient for projected production levels. Transportation of supplies and finished products is

facilitated by interstate highways and railroad access.

1.7    Financial Analysis

1.7.1    Market Analysis

The Colado Operation produces a wide range of finished DE products, which generally fall into one of the following categories:

•

•

Food grade products (filter-aids) sold into the filtration markets are used extensively to filter out contaminants from fruit juices,
wine, beer, sugar, bio-diesel fuel, high fructose corn syrup, and water.

Fine-filler products are used as additives in paints, rubber, paper, and plastics.

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1-7

• Aggregate products, which are used primarily as industrial absorbents, catalysts, and carriers for pesticides.

Based on estimates provided by the U.S. Geological Survey (USGS), the Colado Operation accounted for approximately 10% of the

total production of finished DE products in the U.S. during 2022.

The market for DE is driven by the increasing demand for natural and eco-friendly products, the growing awareness of the benefits

of DE in agriculture and sanitation, and the increasing use of DE in the construction, paint, and coatings industries. Based on the

USGS’s estimates, the compound annual growth rate (CAGR) for domestic DE production between 2018 and 2022 is 3.5%, while

the post-COVID (2019–2022) CAGR is 12.7%.

Strong growth in demand and prices for finished DE products from the Colado Operation is expected. BOYD believes it is

reasonable to assume that pricing will sustain over the remaining life of the Colado Operation.

1.7.2    Capital and Operating Cost Estimates

The Colado Operation’s financial performance over the last years is summarized as follows:

• Average realization (selling price) for finished DE products increased from $491.94 per ton sold in 2020 to $697.27 per ton sold

in 2022.

•

Total cash cost of sales also increased from $328.86 per ton sold in 2020 to $545.48 per ton sold in 2022.

• EBITDA margin decreased from 33.2% in 2020 to 21.8% in 2022.

• Capital expenditures totaled almost $12.5 million over the last three years, averaging $35.97 per ton sold.

Forward-looking production and unit cost estimates are based on actual past performance and subject to U.S. Silica’s customary

internal budget review and approvals process. In BOYD’s opinion, operating volumes are well-defined and understood, as are

mining and processing productivities.

The Colado Operation and related facilities are fully developed and should require no near-term major capital investment to

maintain full commercial production. Historically, the timing and amount of capital expenditures has been largely discretionary and

within U.S. Silica’s control. Their budgetary allocations for sustaining and discretionary capital

JOHN T. BOYD COMPANY

1-8

expenditures over the next three years totals $17.3 million. Thereafter, capital expenditures are expected to rise 3% year-over-year

from 2025’s $5.9 million. BOYD considers the near-term detailed capital expenditure schedule as presented by U.S. Silica to be

reasonable and representative of the capital necessary to operate the Colado Operation.

Operating cost estimates were developed based on recent actual costs and considering specific operational activity levels and cost

drivers. In the near-term, U.S. Silica expects their unit operating costs to stay relatively level (on an uninflated basis). As such, the

projected total cash cost of sales over the life of the mine is $545.48 per ton sold. As the operation is in a steady state, BOYD

considers the future operating cost estimates to be reasonable and appropriate.

1.7.3    Economic Analysis

An economic analysis of the Colado Operation was prepared in-house by U.S. Silica as part of their annual budgeting process. The

financial model forecasts future free cash flow from DE production and sales over the life cycle of the Colado Operation using the

annual forecasts of production, sales revenues, and operating and capital costs.

Table 1.3, below, provides a summary of the estimated financial results for remaining life of the Colado Operation.

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1-9

JOHN T. BOYD COMPANY

Table 1.4 summarizes the results of the pre-tax and after-tax discounted cash flows (DCF) and net present value (NPV) analyses for

the Colado Operation.

1-10

The NPV estimate was made for purposes of confirming the economic viability of the reported DE reserves and not for purposes of

valuing the U.S. Silica, Colado Operation, or its assets. Internal rate-of-return (IRR) and project payback were not calculated, as

there was no initial investment considered in the financial analysis presented herein.

BOYD reviewed the financial model and its inputs in detail, and opined that the model provides a reasonable and accurate reflection

of the Colado Operation’s expected economic performance based on the assumptions and information available at the time of our

review.

1.8    Permitting and Compliance

Numerous permits are required by federal and state law for mining, processing, and related activities at the Colado Operation,

which U.S. Silica reports are in place or pending approval. New permits or permit revisions may be necessary from time to time to

facilitate future operations. Given sufficient time and planning, U.S. Silica should be able to secure new permits, as required, to

maintain its planned operations within the context of current regulations.

U.S. Silica reports having an extensive environmental management and compliance process designed to follow or to exceed

industry standards.

Mine safety is regulated by the U.S. Department of Labor’s Mine Safety and Health Administration (MSHA). MSHA inspects the

facilities a minimum of twice yearly. U.S. Silica’s safety record compares favorably with its regional peers.

BOYD is not aware of any regulatory violation or compliance issue which would materially impact the DE reserve estimate.

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1-11

1.9    Conclusions

It is BOYD’s overall conclusion that U.S. Silica’s estimates of DE reserves, as reported herein: (1) were prepared in conformance

with accepted industry standards and practices, and (2) are reasonably and appropriately supported by technical evaluations, which

consider all relevant modifying factors.

Given the lengthy operating history and status of evolution, residual uncertainty (future risk) for this operation is considered minor

under the current and foreseeable operating environment.

It is BOYD’s opinion that extraction of the DE reported herein is technically, legally, and economically achievable after the

consideration of potentially material modifying factors. The ability of U.S. Silica, or any mine operator, to recover all of the reported

DE reserves is dependent on numerous factors that are beyond the control of, and cannot be anticipated by, BOYD. These factors

include mining and geologic conditions, the capabilities of management and employees, the securing of required approvals and

permits in a timely manner, future product prices, etc. Unforeseen changes in regulations could also impact performance.

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2.0    INTRODUCTION

2.1    Registrant

U.S. Silica is a US-based mining company headquartered in Katy, Texas. The company’s common stock is listed on the New York

Stock Exchange (NYSE:SLCA). U.S. Silica is actively engaged in the production and marketing of commercial DE and performance

materials (DE, calcium bentonite clay, calcium montmorillonite clay, and perlite products). Their whole grain silica products are used

as frac (proppant) sand for oil and natural gas recovery, and in the manufacture of glass, foundry, and building products. U.S.

Silica’s performance materials are used in: (1) filtration for foods and beverages, pharmaceuticals, and swimming pools; (2) as

additives in paint and coatings, plastics and rubber, and agriculture products; and (3) for bleaching, catalysis and adsorption in

edible oil processing, aromatics purification, and industrial and chemical applications. Additional information regarding U.S. Silica

can be found on their website: www.ussilica.com.

2.2    Terms of Reference and Purpose

U.S. Silica retained BOYD to complete an independent technical assessment of their internally-prepared DE resource and reserve

estimates and supporting information for the Colado Operation.

BOYD prepared this technical report summary for U.S. Silica in support of their disclosure of DE reserves for the Colado Operation

in accordance with S-K 1300. The purpose of this report is threefold: (1) to summarize material technical and geoscientific

information for the subject mining property, (2) to provide the conclusions of our technical assessment, and (3) to provide a

statement of DE resources and/or reserves for the Colado Operation.

BOYD’s findings are based on our detailed examination of the supporting geologic and other scientific, technical, and economic

information provided by U.S. Silica, as well as our assessment of the methodology and practices applied by U.S. Silica in

formulating the estimates of DE resources and reserves disclosed in this report. We did not independently estimate DE resources or

reserves from first principles.

We used standard engineering and geoscience methods, or a combination of methods, that we considered to be appropriate and

necessary to establish the conclusions set forth herein. As in all aspects of mining property evaluation, there are uncertainties

JOHN T. BOYD COMPANY

2-2

inherent in the interpretation of engineering and geoscience data; therefore, our conclusions necessarily represent only informed

professional judgment.

The ability of U.S. Silica, or any mine operator, to recover all of the estimated DE reserves presented in this report is dependent on

numerous factors that are beyond the control of, and cannot be anticipated by, BOYD. These factors include mining and geologic

conditions, the capabilities of management and employees, the securing of required approvals and permits in a timely manner,

future DE product prices, etc. Unforeseen changes in regulations could also impact performance. Opinions presented in this report

apply to the site conditions and features as they existed at the time of BOYD’s investigations and those reasonably foreseeable.

This report is intended for use by U.S. Silica, subject to the terms and conditions of its professional services agreement with BOYD.

We also consent to U.S. Silica filing this report as a technical report summary with the SEC pursuant to S-K 1300. Except for the

purposes legislated under US securities law, any other uses of or reliance on this report by any third party is at that party’s sole risk.

2.3    Expert Qualifications

BOYD is an independent consulting firm specializing in mining-related engineering and financial consulting services. Since 1943,

BOYD has completed over 4,000 projects in the United States and more than 60 other countries. Our full-time staff comprises

mining experts in: civil, environmental, geotechnical, and mining engineering; geology; mineral economics; and market analysis. Our

extensive experience in DE resource and reserve estimation combined with our knowledge of the subject property, provides BOYD

an informed basis on which to opine on the reasonableness of the estimates provided by U.S. Silica. An overview of BOYD can be

found on our website at www.jtboyd.com.

The individuals primarily responsible for completing this technical assessment and the preparation of this report are by virtue of their

education, experience, and professional association considered qualified persons (QPs) as defined in S-K 1300.

Neither BOYD nor its staff employed in the preparation of this report have any beneficial interest in U.S. Silica, and are not insiders,
associates, or affiliates of U.S. Silica. The results of our assessment were not dependent upon any prior agreements concerning the
conclusions to be reached, nor were there any undisclosed understandings concerning any future business dealings between U.S.
Silica and BOYD. This report was prepared in return for fees based upon agreed commercial rates, and the payment for

JOHN T. BOYD COMPANY

2-3

our services was not contingent upon our opinions regarding the project or approval of our work by U.S. Silica and its
representatives.

2.4    Principal Sources of Information

Information used in this assignment was obtained from: (1) files provided by U.S. Silica, (2) discussions with U.S. Silica personnel,

(3) records on file with regulatory agencies, (4) public sources, and (5) nonconfidential information in BOYD’s possession.

The following information was provided by U.S. Silica:

• Year-end reserve statements and reports for 2021 and 2022.
• Exploration records (e.g., drilling logs and lab sheets).
• Geologic databases of lithology and sample results.
• Computerized geologic models.
• Mapping data, with:

Land ownership boundaries.
Infrastructure locations.

-
-
- Easement and right-of-way boundaries.
- Surveyed topography (surface elevation).

• Mine plans, production schedules, and supporting data.
• Overview of processing operations and detailed flow sheets.
• Copies of mining and operating permits.
• Historical information, including:

- Production reports.
-
Financial statements.
- Product sales and pricing.

Information from sources external to BOYD and/or U.S. Silica are referenced accordingly.

The data and work papers used in the preparation of this report are on file in our offices.

2.5    Personal Inspections

A site visit and inspection of the Colado Operation was completed on October 12, 2022,

by BOYD’s QPs responsible for the preparation of this report. The site visit included: (1) observation of the active mining operations,

(2) a tour of the mine site’s surface infrastructure, and (3) a tour of the process plant and truck loadouts. BOYD’s representatives

were accompanied by senior U.S. Silica engineering and management personnel who openly and cooperatively answered

questions regarding, but not limited

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to: site history; deposit geology; mining and processing operations; near- and long-range mining plans; and DE marketing.

2.6    Report Version

The DE resources and reserves presented in this Technical Report Summary are effective as of December 31, 2022. The effective

(i.e., “as of”) date of the report is December 31, 2022.

This is the third Technical Report Summary filed by U.S. Silica for the Colado Operation and supersedes the following previously

filed reports:

Westward Environmental; February 2022; Technical Report Summary Colado Site, Lovelock, Pershing County, Nevada.

Westward Environmental; September 2022; Technical Report Summary Colado Site, Lovelock, Pershing County, Nevada.

The user of this document should ensure that this is the most recent disclosure of DE resources and reserves for the Colado

Operation as it is no longer valid if more recent estimates have been issued.

2.7    Units of Measure

The US customary measurement system has been used throughout this report. Tons are short tons of 2,000 pounds-mass. Unless

otherwise stated, currency is expressed in US Dollars ($). Historic prices and costs are presented in nominal (unadjusted) dollars.

Future dollars values are expressed on a constant (unescalated) basis.

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3.0    PROPERTY DESCRIPTION

3.1    Location

Located in Pershing County, Nevada, U.S. Silica’s Colado Operation comprises a surface DE mining operation and a DE processing

plant. The Colado Mine and Colado Processing Plant are located in Pershing County, Nevada, approximately 80 miles northeast of

the City of Reno. Figure 1.1 (page 1-2) shows the general location of the Colado Operation.

The Colado Processing Plant is located seven miles northeast of the City of Lovelock, sandwiched between Business Highway 95

(Upper Valley Road) and Interstate 80 (I-80). The Colado Mine is located approximately 19 miles northwest of the plant via the

paved Seven Troughs Rd. (CR 399).

Geographically, the southeastern-most access to the Colado Mine is located at approximately 40° 16' 29.66" N latitude and 118° 43'

41.51" W longitude. The Colado Processing Plant is located at approximately 40° 14' 45.51" N latitude and 118° 23' 25.35" W

longitude.

3.2    Property Rights

U.S. Silica holds surface and/or mineral rights to approximately 9,526 acres across the two sites that comprise the Colado

Operation. The Colado Mine property comprises ±8,993 acres of private and federal lands leased from the Franco-Nevada and the

BLM, respectively. The Colado Processing Plant property comprises ±533 acres owned in fee by U.S. Silica or leased from the

BLM. Surface and mineral control associated with the Colado Operation is summarized in Table 3.1, below.

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Figures 3.1 and 3.2, on the following pages, illustrate the general layout (including property ownership) of the Colado Mine and

Colado Processing Plant, respectively.

The Franco-Nevada lease provides U.S. Silica with approximately 3,842 acres of surface and mineral control at the Colado Mine.

The lease dates back to 1966 and has been amended several times. The current lease amendment expires in December 2034 and

is expected to be renewed at that time. The Franco-Nevada lease requires annual royalty payments.

The BLM leases provide U.S. Silica with surface control on federal lands at both the Colado Mine and Colado Processing Plant

properties. Mineral rights on the BLM-administered lands at the Colado Mine are provided to U.S. Silica by way of 148 active

mineral claims, of which 132 are placer claims. Mineral claims are renewed on an annual basis and require nominal maintenance

fees.

As shown is Table 3.1, U.S. Silica owns in fee approximately 493 acres upon which the Colado Processing Plant is situated.

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3.3    Encumbrances

3.3.1    Fees and Royalties

To maintain ownership of the Colado Operation properties, U.S. Silica must pay property taxes to the local government in Pershing

County. To BOYD’s knowledge, there are no liens against the properties.

The Franco-Nevada lease agreement requires: (1) annual payment of $45,000, (2) an indexed “per product ton shipped” royalty

which is adjusted annually, and (3) a surcharge of 2.5% of total royalties. For 2022, approximately 54,830 tons were produced from

the Franco-Nevada leases and subject to a $5.75 per ton ($5.90 per ton after 2.5% surcharge) royalty.

In 2022, the annual maintenance fees payable to the BLM were $165 per placer claim.

It is BOYD’s understanding that there are no other royalties, overriding or limited royalties, working interests, production payments,

net profit interests, or other mineral interests in the Colado Operation properties.

3.3.2    Permitting Requirements

Mining and processing activities at the Colado Operation are regulated by several federal and state laws. As mandated by these

laws and regulations, numerous permits are required for mining, processing, and other incidental activities. U.S. Silica reports that

necessary permits are in place or applied for to support immediate operations. New permits or permit revisions may be necessary

from time to time to facilitate future operations. Given sufficient time and planning, U.S. Silica should be able to secure new permits,

as required, to maintain its planned operations within the context of the current regulations. Permitting and permitting conditions are

discussed further in Chapter 17 of this report.

In BOYD’s opinion, U.S. Silica has demonstrated their ability and cooperation to align their operating plans with any permitting

requirements that may be encountered during the normal course of business.

BOYD is not aware of any current material violations or fines imposed by regulators on the Colado Operation.

3.3.3    Mining Restrictions

No significant encumbrances exist at the Colado Mine site.

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3.3.4    Other Significant Factors or Risks

To the extent known to BOYD, there are no other significant factors and risks that may affect access, title, or the right or ability to

perform work on the Colado Operation that are not discussed in this report. However, the reported DE resources and reserves may

be materially impacted by: U.S. Silica’s failure to comply with permit conditions and rules; delays in obtaining required government

or other regulatory approvals or permits; U.S. Silica’s inability to obtain such required approvals or permits; or unforeseen changes

in governmental regulations.

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4.0    PHYSIOGRAPHY, ACCESSIBILITY, AND INFRASTRUCTURE

4.1    Topography, Elevation, and Vegetation

The Colado Operation lies within the Great Basin section of the Basin and Range physiographic province. The terrain is

characterized as a north-south trending series of alternating mountain ranges and wide, flat valleys.

The Colado Mine is located on the western flank of the Trinity Range, a short north-south mountain range extending for about 58

miles. The Trinity Range is flanked to the west by Granite Springs and Sage Valley. The range is characterized by well-dissected

topography with low to moderately steep slopes. Topographic relief within the project area is approximately 1,300 ft. Elevations

range from 4,400 ft above mean sea-level (AMSL) in the northwest, to over 5,700 ft AMSL in the southeast.

There are not any natural surface waters present in and around the Colado Mine.

Vegetation is typical of the Basin and Range physiographic province. The property is covered by sagebrush, grass, and various

other desert shrubs.

4.2    Accessibility

General access to the Colado Operation is via a network of primary and secondary roadways serviced by state and local

governments. The existing roadways provide direct access to the mine and processing facilities and are generally accessible year-

round.

Primary vehicular access to the mine and plant is via I-80, which runs northeast-southwest, from Reno through Lovelock, and

adjacent to the Colado Processing Plant. A combination of state highways and county roads lead to the Colado Mine property,

which is approximately 19 miles northwest of Lovelock, in a rather remote location.

4.3    Climate

The regional climate around the Colado Operation is typical of a high elevation arid desert: little rainfall, warm daytime

temperatures, and cool nighttime temperatures, with seasonably hot summers and cold winters. Average daily high temperatures

are well above freezing 12 months of the year, while daily low temperatures may drop below freezing roughly half of the year.

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The primary cause of the region’s arid climate is the rain shadow effect imparted on the area due to the height of the Sierra Nevada

Mountains to the west. Annual precipitation in the region is approximately 6 to 9 in, however totals may vary widely from year to

year. The evaporation potential greatly exceeds the precipitation on an average annual basis, which aids in drying the mined DE

before processing.

4.4    Infrastructure Availability and Sources

The Colado Processing Plant is located adjacent to the Coal Canyon exit (Exit 112) of I-80 , facilitating the use of semi-trailer trucks

to transport most of the Colado Operation’s finished DE products to customers.

The Colado Processing Plant is also located on a Union Pacific (UP) rail line and can utilize bulk hopper rail cars to transport

finished products, as needed.

Several regional airports are located within a 75-mile radius of the Colado Operation and the Reno-Tahoe International Airport

located just over a 100-mile drive away.

Reliable sources of electrical power, water, gas, supplies, and materials are readily available for the Colado Processing Plant.

Utilities are provided to the plant via suppliers that service the town of Lovelock. The Colado Mine uses diesel generators and solar

panels to provide power to the repair shop and portable job-site office buildings. Diesel fuel must be trucked from the local supplier

and is stored in tanks on site. Water for dust suppression is delivered by the local municipality using tanker trucks and stored on site

in tanks.

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5.0    HISTORY

5.1    Reserve Acquisition

U.S. Silica owns the Colado Operation as a direct result of their purchase of EP Minerals, LLC (EP Minerals) in May 2018. EP

Mineral’s history of developing the Colado Operation dates to the late 1950s, when EP Minerals predecessor, Eagle-Picher,

Industries, Inc., first submitted an operational plan to conduct DE mining on what is the present-day Colado Mine property.

5.2    Exploration and Development

Extensive exploration and mining activities have been conducted at the Colado Mine since the late 1950s. Exploration programs

ranging from geologic mapping, field sampling, drilling campaigns, and specialized survey techniques have been conducted to

investigate the subsurface geology on the property. Early reconnaissance mapped the locations of DE outcrops at the surface of the

Colado Mine property. Field samples were obtained while conducting mapping exercises to gain a general understanding of the

physical and chemical characteristics of the various DE beds located throughout the property. Mapping data and sample testing

results were utilized to identify areas to conduct exploration drilling and sampling. Throughout development of the Colado Mine,

over 1,150 drill holes have been completed.

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6.0    GEOLOGICAL SETTING, MINERALIZATION, AND DEPOSIT

6.1    Regional Geology

The Colado Operation is situated within the Great Basin, a geographical subdivision of the greater Basin and Range province of the

western US. The Great Basin is bounded by the Sierra Nevada Mountains to the west and the Rocky Mountains to the east,

covering much of the State of Nevada, and partially extending into portions of contiguous surrounding states.

Geologically, the Great Basin is predominantly characterized by regional crustal extension. One key characteristic related to this

crustal extension is that all water that falls within the Great Basin watershed drains internally into low-lying areas. This is known as

an endorheic watershed. This process occurs on a regional scale across the entire Great Basin; however smaller-scale sets of

horst-graben structures are locally apparent, and are characterized by the numerous and repetitive sets of generally north-south

trending mountains (horsts) and valleys (grabens). These mountains and valleys are respectively defined by parallel faulting. The

lower-lying graben features, over time, would concentrate drainage, forming playa lakes. As a result, lacustrine (lake) sedimentation

was deposited (DE and volcanic ash sequences mainly). These spatially and temporally related deposits resulted in the

accumulation of similarly characteristic sequences of DE being deposited between 15 to 23 million years ago in the area of the

Colado Operation.

6.2    Local Geology

6.2.1    Stratigraphy

The mineable DE on the Colado property is typically observed as consisting of between two to four beds (varies by pit) separated by

friable tuffaceous (compacted volcanic ash) units. The DE beds are generally white or light pink in color and tend to be very clean,

while the interbedded tuffaceous units are generally gray in color. The contrast in bed coloring makes visual selection during mining

relatively easy.

Welded and lithic tuffs directly overlie the DE beds, with Miocene to Pliocene (Tertiary) age basalt flows forming a weathering-

resistant capping unit, which has helped preserve the underlying strata from being eroded.

Bi-modal Tertiary volcanic units of rhyolitic, basaltic-andesitic, and basaltic composition underlie the DE beds.

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A generalized stratigraphic chart of the surface and near-surface geologic units in Pershing County, Nevada is presented in Figure

6.1.

Figure 6.1: Generalized Stratigraphic Chart, Surface and Near-Surface

Geologic Units, Pershing County, Nevada

The following text discusses the strata encountered in and around the Colado Operation in depositional (ascending) order:

Tertiary Bimodal Volcanic Units

The volcanic units underlying the DE bed sequences on the Colado property consist primarily of andesitic volcanic flows; however,

some degree of additional units have been noted as well, which consist of rhyolitic and basaltic volcanic units. The primary

difference between these types of volcanic deposits is the silica content present in the makeup of the magma at the time of the

eruptions. The exact composition and thickness of the underlying volcanic units is currently unknown.

Tertiary Diatomaceous Earth and Tuff Beds

Miocene age deposits of DE began accumulating during earlier basin-and-range extensional periods in freshwater playa lake

environments, continuing up to approximately 15 million years ago. Intense volcanism during DE depositional periods resulted in

numerous sequences of the accumulating white DE beds being visibly interrupted by intervals of grey friable tuffs. These sequences

are clearly visible in the open pits at the Colado Mine today, where the various DE and tuff beds within the property may vary in

thickness from a few inches thick to more than 50 ft.

Tertiary Tuffs and Basalt Flows

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The DE beds are immediately covered by a series of welded and lithic tuffs, most likely deposited after the playa lake environments

that were accumulating the DE intervals had dried up. Welded and lithic tuffs are simply tuffs that were of such high temperatures

when deposited, that they ended up fusing together while cooling.

These tuffs were then covered by sequences of basaltic lava flows, which may tend to cover very wide areas during eruptions.

These lavas cooled, forming a weathering-resistant cap rock that helped to protect the underlying DE beds from erosion.

Quaternary Alluvium

Often, a thin cover stratum is present, consisting of mixed deposits of alluvium, gravels, sands, soils, or clays, which are typically

concentrated in lower-lying areas where these materials are able to accumulate.

6.2.2    Structural Geology

The Trinity Range is the result of regional uplifting that occurred later during 

basin-and-range extension, after the target DE beds were deposited. Structure within the immediate area is considered to be

relatively simple when compared to other uplifted blocks, as low dip angles (generally less than 10 degrees) are noted in most of the

DE beds being mined.

Several high-angle displacement faults are present in and around the Colado Mine property, however throughout the typical course

of mining (overburden removal and benching into deeper DE beds), these areas are well exposed, allowing modified mining

operations when required.

6.3    Property Geology

Exploration and mining activities have identified several near-surface DE deposits—notably, the Antelope Basin, Atlantis, Horseshoe

Basin, Liberty, Quivera, and Tunnel Hill deposits—on the Colado Mine property. The location of these deposits is illustrated in Figure

6.2, following this text. Figures 6.3 to 6.6, provide typical cross-sections through the various DE deposits on the property.

Surface stratigraphy at the Colado Mine property consists primarily of a combination of Quarternary Alluvium and Tertiary Age

volcanic deposits overlying the target DE beds. U.S. Silica’s drilling logs note variations in overburden materials consisting of soil,

ash, clay, sand, and gravel units over different portions of the Colado Mine. These cover units may be completely absent, exposing

DE at the surface, or they may reach thicknesses in

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excess of 200 ft. When present, the alluvial units typically overlie an interval of more competent basalt material, which overlies a

series of welded and lithic tuffs. The competent overburden intervals must be drilled and blasted in order to expose the DE beds

prior to mining.

The DE beds horizons present as one or more tabular sedimentary units with varying depths, thicknesses, and physical and

chemical characteristics. The DE beds at the Colado Mine are relatively shallow, quite thick, and are moderately dipping. Generally,

the high-quality DE strata are easily distinguished from the surrounding interbedded tuffs and other inclusions by a distinct

difference in color clearly visible in the exposed mining faces.

6.4    Diatomaceous Earth

DE, commonly known as diatomite, is a naturally occurring sedimentary rock that is a result of the accumulation of skeletal remains

of diatoms, which are microscopic single-celled aquatic algae.

Diatoms thrive in various pond, lake, and ocean environments with numerous specialized species in existence, depending on

environmental characteristics. Diatoms convert carbon dioxide into oxygen and organic sugars through the process of

photosynthesis during their short (usually only days long) lifecycle. It is estimated that diatoms produce 20–30% of Earth’s oxygen

and serve as a base food source for the entire aquatic food chain.

Diatom skeletons are composed primarily of amorphous silica (non-crystalline SiO ). The cylindrical shape and high pore volume of

2

these diatom skeletons provide high mechanical strength, natural filtration, and absorption capabilities. The properties which make

DE valuable include low density, high porosity, high surface area, abrasiveness, insulating properties, inertness, absorptive capacity,

brightness, and high silica content. It is mainly used as filter aids, fillers, and absorbents.

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7.0    EXPLORATION DATA

7.1    Background

The Colado Mine has been extensively explored and mined since the late 1950s. Throughout various exploration campaigns, the

subject DE deposits have been identified and delineated through geologic mapping, outcrop sampling, trenching, geophysical

surveys, and extensive exploration drilling.

BOYD was provided source records (drilling logs, testing results, and core photographs), summary reports, and/or databases
compiling the results of 1,153 drill holes located in and around the Colado Mine property. Records indicate that these exploration
data have been collected since the late 1950s.

Much of the exploration data collected prior to U.S. Silica’s purchase of the Colado Mine, is available only in summarized form (i.e.

source records no longer exist). Data verification methodologies outlined by U.S. Silica specifically notes the use of “judgement

calls” to verify or validate exploration data originating before 2010. Verification of the data is often supported by observed geologic

conditions in the expansive mine workings.

7.2    Exploration Procedures

BOYD’s review of the reported methodologies and procedures indicate the exploration data obtained and utilized by U.S. Silica for

the Colado Mine were collected, prepared, and documented, in reasonable compliance with prevailing industry standards, and are

appropriate for use of evaluating and estimating DE resources and reserves.

7.2.1    Geologic Mapping

Basic surficial and mine mapping have been used extensively at the Colado Mine to develop understanding of the stratigraphic,

depositional, and structural relationship of the various rock units.

7.2.2    Drilling

A variety of drilling techniques have been used during the various campaigns, including diamond core, air rotary, sonic, and reverse

circulation.

Air rotary drilling was the primary method utilized to explore the Colado Mine. Records indicate that a truck mounted Reichdrill T-

650-WII air rotary drill was commonly utilized.

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The drill is equipped with a 6-in. hammer assembly, utilizes a 6-in. drill bit and 20-ft drill pipe, and is capable of drilling to depths of

approximately 500 ft. Chipped sample material is continuously obtained during air rotary drilling by placing a 48-in diameter

galvanized pan under the cuttings chute to catch the drill cuttings that are blown back up as the drill bit advances down the hole.

Diamond core drilling methods have also been utilized at the Colado Mine when higher quality samples of the DE intervals are

required for chemical and physical testing. Diamond coring is also utilized in areas that exhibit more complex geologic structures, as

complete core records assist in the definition of bed structure and thickness in such areas. Records indicate that wireline HQ (2.5 in

diameter) drilling methods, capable of reaching depths of 400 ft, were utilized during diamond core drilling campaigns.

Discussions with U.S. Silica personnel indicated that the same general procedural standards in-place at their other operations have

also been implemented since their involvement with the Colado Operation, in order to ensure consistent internal standards are

being followed during drilling and sampling.

7.2.3    Sampling Procedures

Samples collected from the air rotary drilling rig were gathered in five-ft intervals. The cuttings recovered for each interval were

mixed for two minutes in a paddle mixer and then split with a Gilson splitter in the field. The mixing and splitting allows field

personnel to obtain smaller, but representative, samples of each five-ft interval. Samples were placed into canvas or woven cloth

bags and labeled with drill hole identification and sample top and bottom depths. At the end of each day, bagged samples were

delivered to a limited access area at the mine where they were stored before being taken to the company’s internal “dry lab” at their

Vale, Oregon plant for chemical and physical testing.

Cored DE samples, from diamond core drilling, were boxed and labeled at the drill site by U.S. Silica personnel. Boxed core

samples were taken to U.S. Silica’s Fernley, Nevada plant location daily, where the core was examined and geologically logged by

geology staff before being transferred to the dry lab for testing.

7.2.4    Ore Testing

DE samples were analyzed at U.S. Silica’s dry lab, at their Vale, Oregon operation. At the dry lab, the samples were dried, split, and

prepared for chemical and physical testing. Testing was performed on the “natural” split sample and on a muffle burned split.

Standard testing on all samples includes wet bulk density, permeability, and brightness. The muffle burden samples were tested for

soluble metal concentrations.

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Additional standardized testing may be performed for filter aid products on white and pink natural ore, and for natural filler products

when necessary. Non-routine testing, such as x-ray fluorescence, centrifuge wet density, x-ray diffraction, and scanning electron

microscope evaluations to determine diatom genus, are commonly performed at U.S. Silica’s Research and Development

Laboratory in Reno, Nevada.

7.2.5    Other Exploration Methods

BOYD notes that limited trenching and geophysical (gravity, seismic, remote

sensing, resistivity) surveys have reportedly been conducted on the property; however, results from these studies were not provided

for review.

7.3    Exploration Results

7.3.1    Summary of Exploration

Drilling records and summary data indicate that 1,153 drill holes totaling almost 165,000 ft in length—have been completed at the

Colado Mine. The distribution of these drill holes is shown on Figure 7.1, following this page.

A summary of the drilling completed in and around the various DE deposits on the Colado Mine property is presented in Table 7.1:

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7.3.2    Ore Quality

The Colado Operation produces a wide variety of finished DE products for numerous customers. While not all of the finished

products must adhere to a published set of specifications, U.S. Silica utilizes samples obtained during exploration to ascertain the

suitability of the various DE beds for producing the materials it supplies to customers. Additionally, U.S. Silica’s extensive testing of

stockpiled ore provides them flexibility in what, and how much, of a certain mined DE bed is delivered to the Colado Processing

Plant. As such, the Colado Operation has flexibility to meet varying product demands over short timeframes.

7.4    Data Verification

For purposes of this report, BOYD did not verify historic drill hole data by conducting independent drilling. It is customary in

preparing similar mining resource and reserve estimates to accept basic drilling and sample quality data as provided by the client

subject to the reported results being judged representative and reasonable.

BOYD’s efforts to judge the appropriateness and reasonability of the source exploration data included reviewing representative

samples of provided drilling logs, sampling procedures, sample testing results, and discussing various aspects of the mining and

processing operations with U.S. Silica personnel during our site visit. Reviewed drilling records were compared with their

corresponding database records for transcription errors; of which none were found. Exploration data points were compared via

visual and statistical inspection with geologic mapping and cross-sections.

7.5    Adequacy of Exploration and Sampling

BOYD’s review indicates that in general, an acceptable level of drilling and sampling work has been performed at the Colado

Operation. The work completed has been done so by competent personnel in a manner consistent with industry practices. The

amount of data available, combined with the extensive history of mining and producing DE products at the Colado Operation are

sufficient to confirm the extents, uniformity, and continuity of the delineated DE deposits. Similarly, BOYD’s review of sampling data

provided by U.S. Silica suggests that the analyses completed are generally appropriate to determine DE characteristics and

determine the subsequent quality of finished DE products. As such, it is BOYD’s opinion that the exploration and sampling data are

suitable for use in the estimation of DE resources and reserves for the Colado Operation.

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8.0    SAMPLE PREPARATION, ANALYSIS, AND SECURITY

The reader is referred to Sections 7.2 and 7.3 of this report for details regarding sample preparation, analysis, and security.

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9.0    DATA VERIFICATION

BOYD, by way of the data verification processes described in various sections of this report, has used only that data, which were
deemed by the QPs to have been generated with proper industry standard procedures, were accurately transcribed from the original

source, and were suitable to be used for the purpose of preparing estimates of DE resources and reserves.

BOYD’s subject-specific data verification efforts and our conclusions arising therefrom are discussed in the following sections of this
report:

Based on our review, it is BOYD’s overall conclusion that the information made available to us at the time of this report is
representative and reliable for use in estimating the DE resources and reserves of the Colado Operation.

BOYD is not aware of any other limitations on nor failure to conduct appropriate data verification.

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10.0    MINERAL PROCESSING AND METALLURGICAL TESTING

Please refer to Chapter 7 for information regarding mineralogical and chemical testing of the Colado DE deposit.

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11.0    DIATOMACEOUS EARTH RESOURCE ESTIMATE

11.1    Applicable Standards and Definitions

Unless noted, DE resource estimates disclosed herein are done so in accordance with the standards and definitions provided by S-

K 1300. It should be noted that BOYD considers the terms “mineral” and “diatomaceous earth” to be generally interchangeable

within the relevant sections of S-K 1300.

Estimates of mineral resources are always subject to a degree of uncertainty. The level of confidence that can be applied to a

particular estimate is a function of, among other things: the amount, quality, and completeness of exploration data; the geological

complexity of the deposit; and economic, legal, social, and environmental factors associated with mining the resource. By

assignment, BOYD used the definitions provided in S-K 1300 to describe the varying degree of certainty associated with the

estimates reported herein.

The definition of mineral resource provided by S-K 1300 is:

Mineral resource is a concentration or occurrence of material of economic interest in or on the Earth's crust in such form,
grade or quality, and quantity that there are reasonable prospects for economic extraction. A mineral resource is a
reasonable estimate of mineralization, taking into account relevant factors such as cut-off grade, likely mining dimensions,
location or continuity, that, with the assumed and justifiable technical and economic conditions, is likely to, in whole or in part,
become economically extractable. It is not merely an inventory of all mineralization drilled or sampled.

Estimates of mineral resources are subdivided to reflect different levels of geological confidence into measured (highest geologic

assurance), indicated, and inferred (lowest geologic assurance). Please refer to the Glossary of Abbreviations and Definitions for

the meanings ascribed to these terms.

JOHN T. BOYD COMPANY

11-2

11.2    Diatomaceous Earth Resources

11.2.1    Methodology

Based on provided information, U.S. Silica’s geologic modeling and DE resource estimation techniques generally consist of the

following:

1. The top and bottom elevations of various DE beds, and the interbedded waste material intervals (tuff interburden beds), are

interpreted from drill hole records.

2.

Interpreted drill hole records are compiled and validated. The compiled drill hole data are imported into GEOVIA Surpac™
geologic modeling and mine planning software.

3. Wireframe models were developed for each correlated DE bed and geologic block models of the deposits were developed using
industry standard stratigraphic modeling methods. The geologic models delineate the various DE beds and waste units utilizing
blocks sizes ranging from 10 ft by 10 ft by 5 ft to 25 ft by 25 ft by 5 ft (in X, Y, and Z directions), depending on the deposit
geology.

4. Sampling results (assays) were composited on 5-ft lengths constrained within the DE solid models. No grade capping was used.

5. Block grade values were estimated from composited assay values using inverse distance cubed weighting. Search ellipsoids
using 10:10:1 anisotropy were oriented according to the local structure of the various deposits. Three passes with increasing
search distances—200, 400, and 800 ft—were used to estimate the majority of the DE blocks. A maximum number of eight
samples were utilized to estimate the grades of each block.

6. LOM pit shells with designed benches and access ramps were developed with Hexagon Project Evaluator’s pit optimization and

mine planning software. Optimization parameters were derived from historical operating costs and product prices.

7. Estimates of in-place waste and DE volumes were derived from the LOM pit shells and recent topographic (surface elevation)

surveys.

8. An in-place dry bulk density of 0.35 tons per bank cubic yard (0.42 g/cm3) is used to convert the in-place DE volumes to tons.

11.2.2    Estimation Criteria

Development of the DE resource estimate for the Colado Operation assumes mining and processing methods and equipment which

have been utilized successfully at the site for decades.

Within each mining area, the target DE mining horizons present as one or more tabular sedimentary units with varying depths,

thicknesses, and physical and chemical characteristics. Generally, the high-quality DE strata are easily distinguished from the

surrounding interbedded tuffs and other inclusions by a distinct difference in color clearly

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11-3

visible in the exposed mining faces. Selective mining enables the extraction of relatively clean DE.

U.S. Silica has developed numerous pits at the Colado mine where various qualities of DE are mined. Extensive stockpiling capacity

allows for targeted blending to meet finished product specification requirements. Additionally, the Colado Operation has a lengthy

commercial history of producing numerous products with various specifications, allowing nearly all of the identified and mineable DE

intervals to be utilized. As such, the application of cut-off grades is not generally considered in the estimation of DE resources for

the Colado Operation.

The limits of the DE resources are constrained to those portions of the interpreted lithologies that:

• Are reasonably defined by available drilling and sampling data.

• Can produce finished DE products that meet generally accepted specifications.

• Honor any legal mining constraints (e.g., property boundaries, environmental setbacks, utility and infrastructure setbacks, etc.).

• Adhere to physical mining constraints.

• Contain products that can be sold at a profit (i.e., be economic).

DE resources for the Colado Operation are assessed for reasonable prospects for eventual economic extraction by reporting: (1)

only those resources which have been subsequently converted to DE reserves after the application of all material modifying factors,

or (2) those resources which have similar characteristics (i.e., mining conditions, and expected product yields and qualities) to those

converted to DE reserves. The LOM pit shells which constrain the DE resources have been developed using standard pit

optimization techniques and economic parameters derived historical performance.

BOYD has reviewed the criteria employed by U.S. Silica in developing their estimates of DE resources. The parameters are

supported by historical results and align with those employed at similar operations. As such, it is BOYD’s opinion that the stated

criteria are reasonable and appropriate for the estimation of DE resources at the Colado Operation.

11.2.3    Classification

Classification is generally based on the concentration or spacing of exploration data, geological understanding, continuity of

mineralization relative to the style of mineralization, and data quality. The geologic models for the Colado Operation, and

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11-4

consequently the estimates of DE resources derived from them, have been classified on basis of distance from and the number of

assay composites uses to estimate block grades. That is, classification is assigned based on the number of samples available

within defined distances. Table 11.1 provides the general criteria employed in the classification of the DE resources.

BOYD reviewed the classification criteria employed by U.S. Silica with regards to data density, data quality, geological continuity

and/or complexity, and estimation quality. We believe these criteria appropriately reflect the interpreted geology and the estimation

constraints of the deposit. DE resources are well-defined throughout all areas of the mine plan. Observed drill hole spacing

averages approximately 75 ft to 100 ft through a majority of the active mining areas, with future mining areas exhibiting a general

drill hole spacing averaging approximately 100 ft to 500 ft.

11.2.4    Diatomaceous Earth Resource Estimate

Resource estimates of in-situ DE at the Colado Operation as of December 31, 2022, as reported by U.S. Silica are shown in Table

11.2 below. Except as noted, the DE resources presented are inclusive of reserves, not in addition to reserves.

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11-5

As shown, U.S. Silica controls approximately 5.9 million in-place tons of measured and indicated DE resources, inclusive of DE

reserves. In addition, they control approximately 689,000 in-place tons of inferred DE resources. DE resources are not DE reserves

and do not have demonstrated economic viability.

The DE resources shown under the “Planned” column of Table 11.2 include only those in-place tons which are included in U.S.

Silica’s LOM plan for the Colado Operation and therefore considered for conversion to DE reserves. The DE resources shown under

the “Additional” column of Table 11.2 have not been included in the LOM plan and are considered exclusive of (i.e., “in addition to”)

the reported DE reserves. These “Additional” DE resources are considered to have prospects for eventual economic extraction by

virtue of their similarity, in terms of demonstrated extraction methods and expected finished product qualities, to those converted to

DE reserves. However, further studies are required to convert the “Additional” DE resources to DE reserves.

11.2.5    Validation

BOYD was provided with U.S. Silica’s exploration data, geologic models, and volumetric estimates. We have reviewed this

information, on a representative basis, by:

• Verifying the accuracy of geologic model inputs by comparison with drilling logs and laboratory reports.

• Comparing the geologic model with compiled drilling data.

• Confirming estimates of in-place tons and average grades for each pit shell.

It is BOYD’s opinion that the geologic model is representative of the informing data and that the data are of sufficient quality to

support the DE resources estimate provided herein. Furthermore, it is our opinion that the estimation methods and criteria employed

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11-6

are both appropriate and reasonable for the deposit type and proposed extraction methods.

BOYD is not aware of any technical, legal, economic, or other relevant factors that could materially affect the DE resource estimate.

The accuracy of DE resource estimate is, in part, a function of the quality and quantity of available data and of engineering and

geological interpretation and judgment. Given the data available at the time this report was prepared, the estimates presented

herein are considered reasonable. However, they should be accepted with the understanding that additional data and analysis

available after the date of the estimate may result in a change to the current estimate. These revisions may be material. There is no

guarantee that all or any part of the estimated resources will be recoverable.
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12.0    DIATOMACEOUS EARTH RESERVE ESTIMATE

12.1    Applicable Standards and Definitions

Unless noted, DE reserve estimates disclosed herein are done so in accordance with the standards and definitions provided by S-K

1300. It should be noted that BOYD considers the terms “mineral” and “diatomaceous earth” to be generally interchangeable within

the relevant sections of S-K 1300.

Estimates of mineral reserves are always subject to a degree of uncertainty. The level of confidence that can be applied to a

particular estimate is a function of, among other things: the amount, quality, and completeness of exploration data; the geological

complexity of the deposit; and economic, legal, social, and environmental factors associated with mining the reserve. By

assignment, BOYD used the definitions provided in S-K 1300 to describe the varying degree of certainty associated with the

estimates reported herein.

The definition of mineral reserve provided by S-K 1300 is:

Mineral reserve is an estimate of tonnage and grade or quality of indicated and measured mineral resources that, in the
opinion of the qualified person, can be the basis of an economically viable project. More specifically, it is the economically
mineable part of a measured or indicated mineral resource, which includes diluting materials and allowances for losses that
may occur when the material is mined or extracted.

Estimates of mineral reserves are subdivided to reflect geologic confidence, and potential uncertainties in the modifying factors, into

proven (highest assurance) and probable. Please refer to the Glossary of Abbreviations and Definitions for the meanings ascribed

to these terms.

JOHN T. BOYD COMPANY

Figure 12.1, below, illustrates the relationship between mineral resources and mineral reserves.

12-2

Figure 12.1: Relationship Between Mineral Resources and Mineral Reserves

By industry convention, DE reserves are presented on two bases: mineable and saleable. Mineable reserves represent the ROM

tonnage available for excavation and processing. Saleable reserves represent the tonnage of finished DE available for sale after

processing the mineable reserves.

12.2    Diatomaceous Earth Reserves

12.2.1    Methodology

Estimates of DE reserves for the Colado Operation are derived contemporaneously with estimates of DE resources. The Colado

Operation utilizes commercially proven mining and processing methods to extract and process DE from the subject property. The

operation’s production plans are revised periodically to assure that the conversion of in-place to saleable product are: (1) in

reasonable conformity with present and recent historical operational performance, and (2) reflective of expected mining and

processing operations.

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12-3

To derive estimates of mineable tons and saleable product tons (i.e., proven and probable DE reserves), the following modifying

factors were applied to the in-place measured and indicated DE resources underlying the respective mine plan areas:

• Mining recovery factors vary by pit according to expected geologic and mining conditions, and are based on historical

performance. In the LOM plan, mining recovery factors range from 60% to 85%, and average 76.4%. As such, the LOM plan
assumes that approximately 23.6% of the mineable (in-place) DE resource will not be recovered for various reasons. Applying
this recovery factor to the in-place resource results in the estimated ROM DE tonnage (i.e., the mineable DE reserves) that will
be delivered to the process plant.

• An overall 81.6% processing yield. This factor accounts for removal of interbedded waste material and losses in the Colado

Processing Plant due to minor inefficiencies.

The overall product yield (after mining and processing losses) for the Colado Operation is estimated at approximately 62.3%. That

is, for every 100 tons of in-place DE, approximately 62 tons will be recovered and sold as product. Mining recovery and processing

yield factors are derived from historical operating results.

Economic availability of the DE reserves is established by the financial analysis presented in Chapter 19. A long-range average

selling price of $697.27 per product ton has been used to estimate DE reserves for the Colado Operation.

12.2.2    Classification

Proven and probable DE reserves are derived from measured and indicated DE resources, respectively, in accordance with S-K

1300. BOYD is satisfied that the stated DE reserve classification reflects the outcome of technical and economic studies.

12.2.3    Diatomaceous Earth Reserve Estimate

U.S. Silica’s estimated surface mineable DE reserves for the Colado Operation total 3.7 million saleable product tons, as of

December 31, 2022. The DE reserves reported in Table 12.1, on the following page, are based on the approved LOM plan which, in

JOHN T. BOYD COMPANY

BOYD’s opinion, is technically achievable and economically viable after the consideration of all material modifying factors.

12-4

All  of  the  reported  DE  reserves  are  fully  controlled  by  U.S.  Silica  through  the  various  lease  agreements  and  mineral  claims
described in Chapter 3.

The DE reserves of the Colado Operation are well-explored and defined. It is our conclusion that over 37% of the stated reserves

can be classified in the proven reliability category (the highest level of assurance) with the remainder classified as probable. Given

the overall geologic uniformity and history of mining the DE on the Colado property, it is reasonable to assume that some or all of

the probable reserves will be converted to proven reserves upon completion of additional exploration and testing.

The Colado Operation has a well-established history of mining, processing, and selling DE products into various markets. BOYD

has assessed that sufficient studies have been undertaken to enable the DE resources to be converted to DE reserves based on

current and proposed operating methods and practices. Changes in the factors and assumptions employed in these studies may

materially affect the DE reserve estimate.

The extent to which the DE reserves may be affected by any known geological, operational, environmental, permitting, legal, title,

variation, socio-economic, marketing, political, or other relevant issues has been reviewed as warranted. It is the opinion of BOYD

that U.S. Silica has appropriately mitigated, or has the operational acumen to mitigate, the risks associated with these factors.

BOYD is not aware of any additional risks that could materially affect the development of the DE reserves.

Based on our independent review, we have a high degree of confidence that the estimates shown in this report accurately represent

the available DE reserves controlled by U.S. Silica, as of December 31, 2022.

JOHN T. BOYD COMPANY

12-5

12.2.4    Reconciliation with Previous Estimates

When comparing U.S. Silica’s DE reserve estimates as of December 31, 2022, with the estimates presented  for December 31,

1

2021, we note a net increase of approximately 18,000 mineable tons generally resulting from: (1) depletion due to mining of

approximately 175,000 mineable tons, and (2) revisions to mine plans resulting in increases of approximately 193,000 mineable

tons. BOYD does not consider this increase to represent a material change to the DE reserves of the Colado Operation.

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1
 U.S. Silica did not present reserves on a Saleable Tons basis for the 2021 financial year.

JOHN T. BOYD COMPANY

13-1

13.0    MINING METHODS

13.1    Mining Operations

DE mining has been conducted at the Colado Operation since the late 1950s. A number of mining pits have been developed across

the various DE deposits identified on the property. Many of these mine areas have been idled, some depleted, and others included

in the LOM plan for future mining. Table 13.1, below, lists the various mine areas of the Colado Operation.

In 2022, mining activities took place in the Atlantis Pit, and in the Central and South Knob areas of the Horseshoe Basin deposit. All

the other pits are currently idled. Decisions on which deposit(s) to mine is based on several factors including geology, operating

costs, remaining DE reserves, and market demand.

The DE mining horizons at the Colado Mine are relatively shallow, quite thick, and are moderately dipping. These characteristics
favor conventional surface mining techniques using excavators and trucks. Mining occurs on benches, in a stair-like fashion, to

remove the overburden waste material and expose the DE beds. Bench heights vary at each pit but are generally between 20 and

40 ft high.

Sparse organic overburden consisting of sagebrush, juniper, and other desert vegetation is removed along with the basalt cap rock

during overburden stripping campaigns. The basalt cap rock is drilled and blasted by an outside contractor during the winter months

and is subsequently stockpiled for ongoing reclamation activities.

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13-2

Interburden tuff, which is common between the layers of DE, is removed in a similar manner as the basalt cap rock. A third-party

contractor is brought in as needed to drill and blast the interburden. This material is also used for backfilling depleted mining pits

and other reclamation activities.

The DE beds are highly friable; as such, drilling and blasting is not needed to facilitate their excavation. Instead excavators “free

dig” the DE material from the deposit and directly load it into haul trucks. Generally, several passes are needed to fully excavate

each DE bed before the final bench height is reached due to mechanical limitations of the excavator fleet. Figure 13.1, below, shows

the loading operations in the Colado Mine.

Figure 13.1: Loading Operations at the Colado Operation

Excavation of the DE beds occurs from late spring until early fall, a period of roughly 200 days, before wet winter weather impedes

moisture control in the ROM stockpiles. During the winter months, the removal of overburden and other support activities continues

as access to the site is typically available year-round.

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The excavated DE is hauled to one of several different stockpiles located on the Colado Mine property where it is stockpiled for

year-round transportation to the Colado Processing Plant. The Colado Operation maintains a stockpile of approximately 600,000

cubic yards at the mine site to meet the demands of the processing plant. Stockpiled DE usually remains stockpiled for at least one

year to allow the material to dry. This “solar drying” process helps reduce the costs of drying the DE at the Colado Processing Plant.

A loader fills over-the-road semi-trailer trucks with stockpiled ROM material for transportation to the Colado Processing Plant.

Transportation of the ROM material to the processing plant occurs day and night, most of the year.

Waste material from the processing operations is returned to the Colado Mine by the same semi-trailer trucks, where it is unloaded

and used as backfill in exhausted pits.

13.2     Mine Equipment and Staffing

13.2.1     Mine Equipment

The primary mobile equipment involved in mining and transport at the Colado Mine includes:

7 Loaders.
3 Dozers.
13 Articulated Haul Trucks.
5 Excavators.
10 Semi-trailer Trucks.

•
•
•
•
•
• Motor Grader, Water Truck, and other ancillary equipment.

The mobile equipment fleet is comprised of both leased and owned equipment. Regular maintenance requirements and major

rebuilds/repairs of mobile equipment are performed by U.S. Silica personnel or equipment service providers on site at the mine.

If maintained in good condition, the mobile equipment fleet should be capable of achieving production levels required by the LOM

plan.

JOHN T. BOYD COMPANY

    
13.2.2     Staffing

The Colado Operation is staffed by 134 hourly and salaried personnel.

13-4

Staffing levels across the Colado Operation have largely been static since 2018, when U.S. Silica took over operations. The

workforce can be expanded or reduced based on market and seasonal demands. Most employees live nearby in the town of

Lovelock, Nevada.

13.3     Engineering and Planning

The primary mine planning consideration is the safe, economical, and regular supply

of raw DE to the processing plant. In commercial mining terms, the quantities of overburden removed, and DE mined each year at

the Colado Operation are considered modest. The DE deposits afford easy access with its shallow depth and large areal extents. As

such, mining plans for the Colado Mine are relatively simple and very flexible, able to be modified based on demand in a relatively

short time frame.

The following mine design criteria are used to develop the pits shells which constrain the estimated DE resources:

Interramp (overall wall) angle of 45 degrees and bench face angle of 65 degrees.

•
• Bench heights of 20 or 40 ft depending on the dip of DE beds.
• Catch benches at least every 40 ft.

Dewatering before or during mining activities should be manageable with drainage ditches and sumps. Flood waters from localized

flash floods are a manageable risk. Onsite water ponds can be used to hold any excessive storm water.

JOHN T. BOYD COMPANY

13.4     Mining Sequence and Production
Recent annual mine production results and forecasted production over the expected life of the Colado Mine are provided in Figure
13.2, below.

13-5

The proposed mining sequence is illustrated in Figure 13.3, on the following page, and summarized in Table 13.4, below.

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13-6

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13-7

BOYD reviewed the LOM plans for U.S. Silica’s Colado Operation to determine whether the plans: (1) utilize generally accepted

engineering practices, and (2) align with historical and industry norms. Based on our assessment, it is BOYD’s opinion that the

forecasted production levels for the Colado Operation are reasonable, logical, and consistent with typical surface mining practices

and historical results achieved by U.S. Silica.

JOHN T. BOYD COMPANY

13-8

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14.0    PROCESSING OPERATIONS

14.1    Overview

The Colado Operation’s processing facilities are located 24 road miles east of the active mining area near the City of Lovelock,

Nevada. Construction of the processing plant and related infrastructure began in 1959 and was completed shortly thereafter. U.S.

Silica acquired the plant with the rest of the Colado Operation when it bought EP Minerals in 2018.

The production of finished DE products begins when the plant receives raw DE from the mine by truck. From this raw feed material,

numerous products are generated through various processing methods. Figure 14.1, on the next page, presents a simplified

process flow from raw feed delivery to the product distribution.

The processing facility operates 24 hours a day and close to 300 days a year based on a reported 82% average mechanical

availability. The nominal capacity of the facility is currently at 162,000 tons of finished DE products.

BOYD is unaware of any reported interruptions, outages, shortages, or failures related to processing operations which have

materially affected the Colado Operation. Given the operation is well-established, we believe the risk of such events materially

affecting the estimates of DE reserves presented herein is low.

14.1.1    Colado Processing Plant
The processing plant receives its raw DE feed from a stockpile supplied by the mine that is transported by a fleet of semi-trailer
trucks. The raw DE is fed into a hopper at the plant before it is conveyed into a crusher where it is appropriately sized for plant

processes. Oversized material is returned to this crusher until the material is fine enough for processing.

The crude DE is fed into one of three product lines. If needed, crude DE from the bins is metered into a pneumatic conveying
system which dries the material with hot air as it is conveyed. Various mills and cyclones beneficiate the in-process ore before it is
introduced into one of three horizontal rotary kilns. Soda ash is introduced with the DE before entering the kilns as a flux. This helps

the milling process and assists with product coloration. After calcining in the kiln, the DE goes through one final series of mills and
sizing screens before it is: packaged in individual consumer bags and

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14-2

14-3

palletized; packaged in bulk bags to supply larger industrial customers; or, loaded directly into rail cars.

14.2    Production
The Colado Operation’s LOM plan forecasts increased production from the processing plant until the nominal production capacity is

reached. Recent annual production results and forecasted production over the expected life of the operation are provided in Figure
14.2.

14.3    Conclusion
Based on our review, it is BOYD’s opinion that the processing methods and existing equipment at the Colado Processing Plant will
be sufficient for the forecasted production of finished DE products.

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15.0    MINE INFRASTRUCTURE

15.1    Overview

All of the basic infrastructure required for the ongoing operations is in place at the Colado Operation. Figures 3.1 and 3.2 (pages 3-3

and 3-4, respectively) illustrate the general layout of the infrastructure at the Colado Mine and Colado Processing Plant,

respectively.

The surface facilities currently located at the operation are well constructed and have the necessary capacity/capabilities to support

the Colado Operation’s near-term operating plans. Operational preference may lead to the upgrading of some existing facilities if the

operation expands in the future.

BOYD is unaware of any reported interruptions, outages, shortages, or failures related to infrastructure requirements which have

materially affected the Colado Operation. Given the operation is well-established, we believe the risk of such events materially

affecting the estimates of DE reserves presented herein is low.

15.2    Transportation

The Colado Operation is serviced by several roads maintained by the local municipality, county, and state governments. The Colado

Mine site is accessed by using CR 399 (7 Troughs Road) which connects to I-80 near Lovelock, Nevada. The processing plant has

access to Business Highway 95 (Upper Valley Road), which also provides direct access to I-80, east of the plant. These roads are

either paved or well-maintained graded roadways. Road access is typically available year-round.

A rail siding for bulk transportation is in place at the Colado Processing Plant. This railhead is the mainline owned by the UP railroad

along the I-80 corridor. U.S. Silica owns and operates rail loading infrastructure at the plant. In-plant switching is handled by U.S.

Silica with a Trackmobile Railcar Mover to bring in empty cars from the mainline and return loaded ones for the UP to haul away.

15.3    Utilities

Electric power at the mine site is provided by diesel generators and solar power. The processing plant is supplied electric power by

Nevada Energy. The power is delivered by an above-ground network of utility poles running parallel to I-80 from the east and into

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15-2

the plant substation. Power is then distributed by a combination of above and below ground power lines.

Natural gas used by the processing plant is currently supplied by Paiute Pipeline Company (a subsidiary of Southwest Gas) via an

underground pipeline that runs parallel to I-80. The mine site is not supplied with natural gas.

Water for the mine site is primarily used for dust suppression and is trucked in by tanker from a municipal water source. Potable

water is provided by bottles and jugs. Both industrial and potable water for the processing plant is provided by the local municipality

utility company and is delivered via a series of underground pipes.

15.4    Tailings Disposal

The processing of DE at the Colado Processing Plant creates a substantial amount of waste tailings. This waste byproduct is

primarily a combination of opalite, basalt, and clay. The tailings are hauled by U.S. Silica’s semi-trailer truck fleet on their return trip

to the mine site. At the mine site, the tailings are dumped into exhausted pits to be used as fill material during reclamation.

15.5    Other Structures

The mine site has few structures. Currently a maintenance shelter used to service the mining equipment and a small portable office

reside on site.

The processing plant has undergone several upgrades and changes over its 50+ years of operation. In addition to the plant itself,

the site also contains:

• Office buildings that host engineering, financial and administrative staff.
• Several support buildings for housing machinery and maintenance activities.
• A warehouse for material storage and product bagging.
• Several product loadouts.
• Various pump structures and outbuildings.

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16.0    MARKET STUDIES

16.1    Product Specifications

The Colado Operation is part of U.S. Silica’s Industrial & Specialty Products (ISP) business segment. The ISP unit produces

products that are used as filter aids, absorbents, and functional additives for a variety of industries including food and beverage,

biofuels, recreational water, oil and gas, farm and home, landscape, sports turf, paint, plastics, and insecticides.

The Colado Operation produces a wide range of finished DE products, which generally fall into one of the following categories:

•

•

Food grade products (filter-aids) sold into the filtration markets are used extensively to filter out contaminants from fruit juices,
wine, beer, sugar, bio-diesel fuel, high fructose corn syrup, and water.

Fine-filler products are used as additives in paints, rubber, paper, and plastics.

• Aggregate products, which are used primarily as industrial absorbents, catalysts, and carriers for pesticides.

In terms of sales volume, the aggregate products are significantly smaller compared to the filtration and filler products.

16.2    Historical Sales

Recent historical sales figures provided by U.S. Silica for the Colado Operation are summarized in Table 16.1, below.

Over the past three years, the average selling price (ASP) for the Colado Operation’s finished DE products increased almost 42%.

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16-2

According to sales information provided by U.S. Silica for the Colado Operation:

• Contract sales account for roughly 30% of total product sales.

•

The top-five customer by sales revenue account for approximately 18% of total sales.

Based on estimates provided by the USGS, the Colado Operation accounted for approximately 10% of the total production of

finished DE products in the U.S. during 2022.

BOYD is not aware of any material contracts for the sale of finished DE products from the Colado Operation.

16.3    Market Outlook

The market for DE is driven by the increasing demand for natural and eco-friendly products, as well as the growing awareness of

the benefits of DE in agriculture and sanitation, as well as the increasing use of DE in the construction, paint, and coatings

industries.

The DE market is segmented by product type, application, and geography. By product type, the market is segmented into food and

filter grade. By application, the market is segmented into agriculture, construction, paint and coatings, animal feed, and others.

Geographically, the market is driven by transportation costs. While many materials can be substituted for DE, its unique properties

assure its continued use in many applications.

According to the USGS, the amount of produced DE sold in US has generally increased year-over-year, excepting a small dip in

2019 and 2020 as the result of decreased demand due to the COVID-19 pandemic. It should be noted that the Colado Operation

production did not suffer a similar dip during COVID-19 pandemic. Based on the USGS’s estimates, the CAGR for domestic DE

production between 2018 and 2022 is 3.5%, while the post-COVID (2019–2022) CAGR is 12.7%.

Strong growth in demand and increased prices for finished DE products from the Colado Operation are expected. BOYD believes it

is reasonable to assume that pricing will sustain over the remaining life of the Colado Operation.

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17.0    PERMITTING AND COMPLIANCE

17.1    Permitting

Numerous permits are required by federal, state, and municipal law for mining, processing, and related activities at the Colado

Operation. U.S. Silica reports that necessary permits to support current and near-term operations are in place or pending approval.

New permits or permit revisions may be necessary from time to time to facilitate future operations. Given sufficient time and

planning, U.S. Silica should be able to secure new permits, as required, to maintain its planned operations within the context of

current regulations.

A description of the salient permitting requirements for the Colado Operation follows.

Surface mining of private and BLM land at Colado is authorized under U.S. Silica’s Mine Plan of Operations NVN-065329 and

Nevada Reclamation Permit No. 0182. U.S. Silica has updated or amended the permits over the course of operation to enable

mining of increasing areas of the property. Surety bonds totaling approximately $16.1 million have been submitted to the BLM in

Nevada to underwrite permit reclamation requirements.

U.S. Silica utilizes a Spill Prevention, Controls and Countermeasure (SPCC) Plan at the Colado Operation to address requirements

of the Federal Oil Pollution Prevention Regulations (40 CFR Part 112). The SPCC Plan establishes oil spill preparedness,

prevention, planning, response, and notification procedures per the federal regulations and addresses state-specific oil spill

reporting notification and response requirements as administered by the Nevada State Emergency Response Commission.

The Nevada Division of Water Resources authorizes the annual use of up to 1,052 acre-feet of groundwater through Permit Nos.

87089, 18091, 24074, 7558, and 5238. Monthly reporting and metering are required. This water is trucked to the mine site for dust

suppression.

U.S. Silica holds several permits authorized by the NDEP, including a Class I Air Quality Operating Permit No. AP1499-3768, Class

II Surface Area Disturbance Permit No. AP1499-0862.04, and a Class III Landfill Waiver No. SWW1713.

JOHN T. BOYD COMPANY

17-2

The Nevada State Fire Marshal has issued the following Hazardous Materials Permits to U.S. Silica:

• Hazardous Materials Permit No. 95886 for hazardous materials/fuels at the mine.

• Hazardous Materials Permit No. 95888 for hazardous materials/fuels at the mine shop.

• Hazardous Materials Permit No. 101676 for hazardous materials/fuels at the processing plant.

U.S. Silica is in the process of acquiring a Nevada Industrial Stormwater Multisector General Permit No. NVR050000 which will

authorize the discharge of water from the processing plant site in the event of a 2-year, 24-hour storm. This permit is currently

pending approval.

17.2    Compliance

U.S. Silica reports having an extensive environmental management and compliance process designed to follow or to exceed

industry standards.

In their 2021 corporate sustainability report, U.S. Silica reports:

•

•

Increasing the use of renewable energy sources.

Improving the quality of local water by utilizing best-in-class tailings management techniques.

• Recycling or reusing tailings waste for land reclamation.

Mine safety is regulated by the MSHA. MSHA inspects the facilities a minimum of twice yearly. U.S. Silica’s safety record compares

favorably with its regional peers.

Based on our review of information provided by U.S. Silica and available public information, it is BOYD’s opinion that the Colado

Operation’s record of compliance with applicable mining, water quality, and environmental regulations is generally typical for that of

the industry. BOYD is not aware of any regulatory violation or compliance issue which would materially impact the DE reserve

estimate.

JOHN T. BOYD COMPANY

17-3

17.3    Post-Mining Land Use and Reclamation

Disturbed areas at the Colado Operation must be reclaimed in accordance with approved reclamation and abandonment plans.

These plans are a condition of U.S. Silica’s operating permits and licenses and generally require:

• Regrading and landscaping of all disturbed areas.
• Regrading and landscaping of stockpiles.
• Removal of all equipment and structures.
• Regrading and landscaping of disused roads.
• Destruction or breaching of any dams or impoundments.
• Disposal of all hazardous wastes.

Mine site reclamation costs are funded from U.S. Silica’s Asset Retirement Obligations (ARO) account. Funding of the ARO account

is included in the Colado Operation’s operating costs discussed in Chapter 18 and included in the economic analysis presented in

Chapter 19. ARO costs estimates are reviewed annually and current estimated at approximately $16.1 million for the Colado

Operation. As a matter of good mining practice, U.S. Silica seeks to conduct progressive reclamation throughout the operation’s

mining life to minimize risk and costs at closure.

17.4    Community Engagement

The Colado Operation has been a fixture in the Lovelock, Nevada community since the late-1950s. U.S. Silica is one of the major

employers and economic contributors in the area. BOYD is unaware of any plans, negotiations, agreements with local individuals or

groups or commitments to ensure local procurement and hiring.

U.S. Silica’s corporate sustainability report outlines the components of its core community engagement initiatives. It's stated

priorities include increasing charitable contributions to organizations that support the local community and actively seeking

opportunities for volunteering and community engagement.

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JOHN T. BOYD COMPANY

18-1

18.0    CAPITAL AND OPERATING COSTS

18.1    Historical Financial Performance

Table 18.1 summarizes the past three years of financial data for the Colado Operation.

Gross revenues include income from product sales and shipping.

Total cash costs of sales include operating costs (i.e., mining, ongoing reclamation, processing, product loadout, and other related

costs) in addition to selling, general, and administrative expenses.

Capital expenditures include maintenance (sustaining) expenses and discretionary spending on continuous improvement projects to

drive and maintain cost efficiencies.

Based on the financial data presented above:

• Average realization (selling price) for finished DE products increased from $491.94 per ton sold in 2020 to $697.27 per ton sold

in 2022.

•

Total cash cost of sales also increased from $328.86 per ton sold in 2020 to $545.48 per ton sold in 2022.

• EBITDA margin decreased from 33.2% in 2020 to 21.8% in 2022.

• Capital expenditures totaled almost $12.5 million over the three years, averaging $35.97 per ton sold.

JOHN T. BOYD COMPANY

18-2

18.2    Estimated Costs

The production and unit cost estimates provided by U.S. Silica are based on actual past performance and their customary internal

budget review and approvals process. Operating volumes are well-defined and understood, as are mining and processing

productivities. As such, it is BOYD’s opinion that the production and financial projections are reasonable and are likely to be within

±20% accuracy level.

This section contains forward-looking information related to capital and operating cost estimates for the Colado Operation.

There are inherent known and unknown risks and uncertainties associated with all mining operations. These risks, uncertainties,

and other factors are not quantifiable, but include or are not limited to, adverse general economic conditions, operating hazards,

inherent uncertainties in interpreting engineering and geologic data, fluctuations in commodity prices and prices for operational

services, government regulation and political risks, as well as other risks commonly associated with the mining industry.

18.2.1    Projected Capital Expenditures

The Colado Operation and related facilities are fully developed and should not require any near-term major capital investment to

maintain full commercial production. Historically, the timing and amount of capital expenditures has been largely discretionary and

within U.S. Silica’s control. Their budgetary allocations for sustaining and discretionary capital expenditures over the next three

years is provided in Table 18.2, below.

BOYD considers the near-term detailed capital expenditure schedule as presented by U.S. Silica to be reasonable and
representative of the capital necessary to operate the Colado Operation.

JOHN T. BOYD COMPANY

18-3

After 2025, capital expenditures are projected to increase 3% per year from 2025s level until the end of operation’s life. As the
Colado Operation is in a steady state of production, the projected capital expenditures are considered reasonable and expected.

18.2.2    Projected Operating Costs
Operating cost estimates were developed based on recent actual costs and considering specific operational activity levels and cost
drivers. The estimates consider current and expected labor headcount and salaries, major consumables and unit prices, power
costs, and equipment and maintenance costs. The total operating cost estimate includes all site costs related to mining, processing,
and general and administrative activities.

In the near-term, U.S. Silica expects their unit operating costs to stay relatively consistent (on an uninflated basis). As such, the

projected total cash cost of sales over the life of the mine is $545.48 per ton sold. As the operation is in a steady state, BOYD

considers the future operating cost estimates to be reasonable and appropriate.

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JOHN T. BOYD COMPANY

19-1

19.0    ECONOMIC ANALYSIS

19.1    Approach

The economic analysis presented in this chapter was made for the purposes of confirming the commercial viability of the Colado

Operation’s reported DE reserves and not for the purposes of valuing U.S. Silica, the Colado Operation, or its assets. The economic

analysis contains forward-looking information related to the projected operating and financial performance of the Colado Operation

and therefore involves inherent known and unknown risks and uncertainties, some of which may be outside of U.S. Silica’s control.

U.S. Silica, as with all mining companies, actively evaluates, changes, and modifies business and operating plans in response to

various factors that may affect operational and/or financial results. Actual results, production levels, operating expenses, sales

realizations, and all other modifying factors could vary significantly from the assumptions and estimates provided in this analysis.

Risk is subjective, as such, BOYD recommends that each reader should evaluate the project based on their own investment criteria.

The financial model used for the purposes of the economic analysis has been prepared in-house by U.S. Silica as part of their

annual budgeting process. The model forecasts future free cash flow from DE production and sales over the life cycle of the Colado

Operation using the annual forecasts of production, sales revenues, and operating and capital costs discussed earlier in this report.

A DCF analysis, in which future free cash flows are discounted to present value, is used to derive a NPV for the DE reserves. Use

of DCF-NPV analysis is a standard method within the mining industry to assess the economic value of a project after allowing for

the cost of capital invested.

The financial evaluation of the Colado Operation has been undertaken on a simplified after-tax basis and does not reflect U.S.

Silica’s corporate tax structure. NPV is calculated using an after-tax discount rate of 12.5% (NPV ). Cash flows were assumed to

12.5

occur in the middle of each year and are discounted to mid-year 2022. Cost estimates and other inputs to the cash flow model for

the project have been prepared using constant 2022 money terms, i.e., without provision for inflation. IRR and project payback were

not calculated, as there was no initial investment (sunk costs) considered in the financial model provided herein.

JOHN T. BOYD COMPANY

19-2

A suite of sensitivities was calculated to evaluate the effect of the main drivers of economic performance, including variations in

sales prices, operating costs, and capital costs.

BOYD has reviewed the financial model and its inputs in detail. It is our opinion that the financial model provides a reasonable and

accurate reflection of the Colado Operation’s expected economic performance based on the assumptions and information available

at the time of our review.

19.2    Assumptions and Limitations

Cash flow projections for the Colado Operation have been generated from the annual forecasts of production, sales revenues, and

operating and capital costs discussed earlier in this report. A summary of the key assumptions and limitations is provided below:

• Sales volumes of finished DE are expected to increase 3% per annum (limited by processing plant capacity of 160,000 product

tons per year) while maintaining a consistent product mix.

• ROM production requirements are based on an expected processing yield of 81.6% (the historic average) and are also projected
to increase 3% per annum until plant capacity is reached. Forecasted ROM production is at or below the capacity of the existing
mining equipment and related infrastructure.

•

Forecasted revenues are based on sales of various grades of finished DE with a weighted-average sales price of $697.27 per
ton.

• Capital and operating costs are discussed in Chapter 18. Capital expenditures are derived from budgetary allocations for the

first three years of the forecast and escalated thereafter at 3% per annum. Unit operating costs are expected to remain relatively
constant over the life of the operation at $545.48 per sold ton.

•

Taxes are based on combined Federal and State Tax rates totaling 26%.

• Buildup of net working capital is equal to 25% of positive cash (operating) margins.

• Depreciation and amortization expenses are estimated as the average of the proceeding three years.

• No asset recovery/salvage values were included in the valuation.

19.3    Financial Model Results

Estimated LOM pre-tax and after-tax cash flows for DE production from the Colado Operation are presented in Table 19.1, on the

following page.

JOHN T. BOYD COMPANY

19-3

JOHN T. BOYD COMPANY

Table 19.2, below, provides a summary of the estimated remaining life of mine financial results for the Colado Operation.

19-4

DCF-NPV on a pre-tax and after-tax basis, using discount rates of 10%, 12.5% (the base case), and 15%, were calculated utilizing

the projected cash flows. Table 19.3 summarizes the results of the pre-tax and after-tax DCF-NPV analyses:

As shown, the pre-tax DCF-NPV ranges from approximately $93.8 million to $131.2 million. The after-tax DCF-NPV ranges from

approximately $70 million to $97 million.

The economic analysis confirms that the Colado Operation generates positive pre- and after-tax financial results and a real NPV

12.5

of $81.6 million. As such, it is BOYD’s opinion that the Colado Operation’s DE reserves have demonstrated economic viability.

JOHN T. BOYD COMPANY

19-5

19.4    Sensitivity Analysis

Table 19.4, below, shows the sensitivity of the project after-tax for a cash flow discounted at 12.5% (NPV ) to a variation over a

12.5

range of 20% above and below the base case in: (1) average selling prices and (2) operating costs.

As might be expected, the project is most sensitive to changes in product pricing and operating costs. The Colado Operation

generates negative value only if costs are increased substantially and/or selling prices are reduced significantly.

The project is less sensitive to capital costs. There is little to no impact varying the capital costs from 70% to 130% of the base

case.

This analysis demonstrates the project value to be relatively robust; with positive NPVs reported across the range of values

assessed.

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JOHN T. BOYD COMPANY

20-1

20.0    ADJACENT PROPERTIES

There is no information used in this report that has been sourced from adjacent properties. BOYD is unaware of any mining or

exploration activities having occurred on the adjacent properties.

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JOHN T. BOYD COMPANY

21-1

21.0    OTHER RELEVANT DATA AND INFORMATION

BOYD is not aware of any additional information which would materially impact the DE resource and reserve estimates reported

herein.

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JOHN T. BOYD COMPANY

22-1

22.0    INTERPRETATION AND CONCLUSIONS

22.1    Audit Findings

BOYD’s independent technical assessment was conducted in accordance with S-K 1300 and concludes:

• Sufficient data have been obtained through site exploration and sampling programs and mining operations to support the

geological interpretations of the DE deposit within the controlled property of the Colado Operation. The data are of sufficient
quantity and reliability to reasonably support the DE resource and reserve estimates presented in this report.

• BOYD is of the opinion that our data verification efforts: (1) adequately confirm the reasonableness of the geologic
interpretations, resource estimation criteria, and economic assumptions; and (2) support the use of the data in DE
resource/reserve estimation.

•

•

•

The nearly 3.7 million saleable product tons of DE reserves (as of December 31, 2022) identified on the property are reasonably
and appropriately supported by technical studies, which consider expected geologic conditions, planned mining and processing
operations, forecasted product revenues, and operating and capital cost estimates. As such, BOYD is of the opinion that there
are reasonable expectations that the stated DE reserves for the Colado Operation are technically, economically, and legally
extractable as of December 31, 2022.

In addition to the reported reserves, U.S. Silica controls approximately 689,000 in-place tons of inferred DE resources at the
Colado Operation. It is BOYD’s opinion that the stated DE resources have been reported using economic and mining
assumptions which support the reasonable potential for eventual economic extraction.

There is no other relevant information material to the Colado Operation that is necessary to make this technical report summary
not misleading.

22.2    Significant Risks and Uncertainties

As a mining operation with a lengthy operating history, the purpose of U.S. Silica’s periodic mine planning exercises is to: (1) collect

and analyze sufficient data to reduce or to eliminate risk in the technical components of the project, and (2) to refine economic

projections based on current data. There is a high degree of certainty for this project under the current and foreseeable operating

environment. A general assessment of risk is presented in the relevant sections of this report.

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JOHN T. BOYD COMPANY

23-1

23.0    RECOMMENDATIONS

Based on the scope of our assignment, BOYD has no recommendations regarding the Colado Operation. It is our understanding

that U.S. Silica continuously reviews and improves operating practices as a matter of course.

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JOHN T. BOYD COMPANY

24-1

24.0    REFERENCES

A list of supporting information is provided in Section 2.4. Additional references are cited as footnotes in the report as required.

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JOHN T. BOYD COMPANY

25-1

25.0    RELIANCE ON INFORMATION PROVIDED BY REGISTRANT

In the preparation of this report, BOYD has relied, exclusively and without independent verification, upon information furnished by

U.S. Silica as presented in Table 25.1, below.

BOYD exercised due care in reviewing the information provided by U.S. Silica within the scope of our expertise and experience

(which is in technical and financial mining issues) and concluded the data are reasonable and appropriate considering the status of

the subject properties and the purpose for which this report was prepared. We have no reason to believe that any material facts

have been withheld or misstated, or that further analysis may reveal additional material information. However, the accuracy of the

results and conclusions of this report are reliant on the accuracy of the information provided by U.S. Silica.

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JOHN T. BOYD COMPANY

TECHNICAL REPORT SUMMARY

PROPPANT SAND RESOURCES AND RESERVES

LAMESA OPERATION

Dawson County, Texas

Prepared For

U.S. SILICA COMPANY

Katy, Texas

By

John T. Boyd Company

Mining And Geological Consultants

Pittsburgh, Pennsylvania

Report No. 3076.018
FEBRUARY 2023

 JOHN T. BOYD COMPANY

    Mining and Geological Consultants

February 22, 2023

JOHN T. BOYD COMPANY

 JOHN T. BOYD COMPANY

    Mining and Geological Consultants

File: 3076.018

U.S. Silica Company
24275 Katy Freeway, Suite 600
Katy, TX 77494-7271

Attention:    Mr. Terry Lackey

    Mining Director

Subject:    Technical Report Summary
        Proppant Sand Resources and Reserves
        Lamesa Operation
        Dawson County, Texas

Ladies and Gentlemen:

The John T. Boyd Company (BOYD) was retained by U.S. Silica Company (U.S. Silica) to complete an independent technical
assessment of the proppant sand resource and reserve estimates for the Lamesa Operation as of December 31, 2022.

This technical report summary: (1) summarizes material technical and geoscientific information for the subject mining property, (2)
provides the conclusions of our technical assessment, and (3) provides a statement of proppant sand resources and reserves for
the Lamesa Operation.

Respectfully submitted,

JOHN T. BOYD COMPANY

By:

John T. Boyd II
President and CEO

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JOHN T. BOYD COMPANY

    TABLE OF CONTENTS

    Page
LETTER OF TRANSMITTAL

TABLE OF CONTENTS

GLOSSARY AND ABBREVIATIONS

1.0    EXECUTIVE SUMMARY     1-1
    1.1    Introduction     1-1
    1.2    Property Description     1-1
    1.3    Geology     1-3
    1.4    Exploration     1-3
    1.5    Proppant Sand Resources and Reserves     1-4
    1.6    Operations     1-5
        1.6.1    Mining     1-5
        1.6.2    Processing     1-5
        1.6.3    Other Infrastructure     1-6
    1.7    Financial Analysis     1-7
        1.7.1    Market Analysis     1-7
        1.7.2    Capital and Operating Cost Estimates     1-7
        1.7.3    Economic Analysis     1-8
    1.8    Permitting Requirements     1-10
    1.9    Conclusions     1-10

2.0    INTRODUCTION     2-1
    2.1    Registrant     2-1
    2.2    Terms of Reference and Purpose     2-1
    2.3    Expert Qualifications     2-2
    2.4    Principal Sources of Information     2-3
    2.5    Personal Inspections     2-3
    2.6    Report Version     2-4
    2.7    Units of Measure     2-4

3.0    PROPERTY DESCRIPTION     3-1
    3.1    Location     3-1
    3.2    Property Rights    3-1    
    3.3    Encumbrances    3-1
        3.3.1 Fees and Royalties    3-1
        3.3.2 Permitting Requirements    3-3
        3.3.3 Mining Restrictions    3-3
        3.3.4 Other Significant Factors or Risks    3-3

4.0    PHYSIOGRAPHY, ACCESSIBILITY, AND INFRASTRUCTURE     4-1
    4.1    Topography, Elevation, and Vegetation     4-1
    4.2    Accessibility     4-1
    4.3    Climate    4-1
    4.4    Infrastructure Availability and Sources     4-2

JOHN T. BOYD COMPANY

        
    
        
    TABLE OF CONTENTS    - Continued  

    Page

5.0    HISTORY     5-1
    5.1    Reserve Acquisition     5-1
    5.2    Mine Development     5-1

6.0    GEOLOGICAL SETTING, MINERALIZATION, AND DEPOSIT     6-1
    6.1    Regional Geology     6-1
    6.2    Local Geology     6-1
        6.2.1    General Stratigraphy     6-1
        6.2.2    Structural Geology     6-2
    6.3    Property Geology     6-3

7.0    EXPLORATION DATA     7-1
    7.1    Background     7-1
    7.2    Exploration Procedures     7-1
        7.2.1    Drilling     7-1
        7.2.2    Sampling Procedures    7-2
        7.2.3    Sand Testing     7-3
        7.2.4    Other Exploration Methods     7-4
    7.3    Exploration Results     7-4
        7.3.1    Summary of Exploration     7-4
        7.3.2    Sand Quality    7-4
        7.3.3    Grain Size Distribution    7-6
        7.3.4    Proppant Sand Quality    7-6
    7.4    Data Verification     7-7
    7.5    Adequacy of Exploration and Sampling    7-8

8.0    SAMPLE PREPARATION, ANALYSIS, AND SECURITY     8-1

9.0    DATA VERIFICATION     9-1

10.0    MINERAL PROCESSING AND METALLURGICAL TESTING     10-1

11.0    PROPPANT SAND RESOURCE ESTIMATE     11-1
    11.1    Applicable Standards and Definitions     11-1
    11.2    Proppant Sand Resources     11-2
        11.2.1     Methodology     11-2
        11.2.2     Estimation Criteria     11-2
        11.2.3     Classification     11-3
        11.2.4     Proppant Sand Resource Estimate     11-5
        11.2.5     Validation     11-5

12.0    PROPPANT SAND RESERVE ESTIMATE     12-1
    12.1    Applicable Standards and Definitions     12-1
    12.2    Proppant Sand Reserves     12-2
        12.2.1     Methodology    12-2
        12.2.2     Classification    12-3
        12.2.3     Proppant Sand Reserve Estimate    12-5
        12.2.4     Reconciliation with Previous Estimates     12-6

JOHN T. BOYD COMPANY

    
    
    
    TABLE OF CONTENTS    - Continued  

    Page

13.0    MINING METHODS     13-1
    13.1    Mining Operation    13-1
    13.2    Mine Equipment and Staffing     13-2
        13.2.1     Mine Equipment     13-2
        13.2.2     Staffing     13-2
    13.3    Engineering and Planning     13-3
    13.4    Mining Sequence and Production     13-3

14.0    PROCESSING OPERATIONS     14-1
    14.1    Overview     14-1
        14.1.1 Wet Processing Plant    14-1
        14.1.2 Dry Processing Plant    14-3
    14.2    Production     14-3
    14.3    Conclusion     14-3

15.0    MINE INFRASTRUCTURE     15-1
    15.1    Overview     15-1
    15.2    Transportation     15-1
    15.3    Utilities    15-1
    15.4    Tailings Disposal    15-2
    15.5    Other Structures    15-2

16.0    MARKET STUDIES     16-1
    16.1    Market Overview     16-1
    16.2    Historical Sales     16-2
    16.3    Market Outlook     16-2

17.0    PERMITTING AND COMPLIANCE     17-1
    17.1    Permitting     17-1
    17.2    Compliance     17-2
    17.3    Post-Mining Land Use and Reclamation    17-3
    17.4    Community Engagement    17-3

18.0    CAPITAL AND OPERATING COSTS     18-1
    18.1    Historical Financial     18-1
    18.2    Estimated Costs     18-2
        18.2.1 Projected Capital Expenditures     18-2
        18.2.2 Projected Operating Costs    18-3

19.0    ECONOMIC ANALYSIS     19-1
    19.1    Approach     19-1
    19.2    Assumptions and Limitations     19-2
    19.3    Financial Model Results    19-2
    19.4    Sensitivity Analysis    19-5

20.0    ADJACENT PROPERTIES     20-1

JOHN T. BOYD COMPANY

        
    
    TABLE OF CONTENTS    - Continued  

    Page

21.0    OTHER RELEVANT DATA AND INFORMATION     21-1

22.0    INTERPRETATION AND CONCLUSIONS     22-1
    22.1    Audit Findings     22-1
    22.2    Significant Risks and Uncertainties     22-1

23.0    RECOMMENDATIONS     23-1

24.0    REFERENCES     24-1

25.0    RELIANCE ON INFORMATION PROVIDED BY REGISTRANT     25-1

JOHN T. BOYD COMPANY

    TABLE OF CONTENTS    - Continued  

    Page

List of Tables
1.1    Lamesa Operation Proppant Sand Resources (as of December 31, 2022)    1-4
1.2    Lamesa Operation Proppant Sand Reserves (as of December 31, 2022)     1-4
1.3    Financial Results    1-9
1.4    DCF-NPV Analysis    1-9
7.1    Weighted Average Particle Size Distribution    7-6
7.2    Lamesa Operation Proppant Sand Characteristics    7-7
11.1    Proppant Sand Resource Classification Criteria    11-4
11.2    Lamesa Operation Proppant Sand Resources (as of December 31, 2022)    11-5
12.1    Lamesa Operation Proppant Sand Reserves (as of December 31, 2022)    12-5
13.1    Employees by Classification    13-2
16.1    Historical Sales Data     16-2
18.1    Historical Financials    18-1
18.2    Projected Capital Costs    18-2
19.1    Annual Production and Cash Flow Forecast Lamesa Operation     19-3
19.2    Financial Results    19-4
19.3    DCF-NPV Analysis     19-4
19.4    After-Tax NPV  Sensitivity Analysis ($ millions)     19-5
25.1    Information Relied Upon from Registrant    25-1

12.5

JOHN T. BOYD COMPANY

    TABLE OF CONTENTS    - Continued  

    Page

List of Figures
1.1    General Location Map     1-2
3.1    Map Showing Site Layout Lamesa Operation     3-2
6.1    Generalized Stratigraphic Chart Surficial Deposits of Dawson
    County, Texas    6-1
6.2    Map Showing Proppant Sand Thickness Isopaches Lamesa Operation    6-4
6.3    Cross-Section A – A’ Lamesa Operation    6-5
7.1    Map Showing Drill Hole Locations Lamesa Operation    7-5
12.1    Relationship Between Mineral Resources and Mineral Reserves    12-2
12.2    Map Showing Mineral Reserve Classification Lamesa Operation    12-4
13.1    Loading Operations at the Lamesa Operation    13-1
13.2    Recent Historical and LOM Forecasted Mining Production    13-3
13.3    Map Showing Life-of-Mine Plan Lamesa Operation    13-5
14.1    Simplified Flow Sheet Lamesa Operation    14-2
14.2    Recent Historical and LOM Forecasted Processing Plant Production    14-3

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1

000

$

%

AEI

AMSL

API

ARO

ASP

ASTM

BNSF

BOYD

CapEx

Constant Dollar

CSX

DCF

Discount Rate

E&P

EBIT

EBITDA

ESA

Frac Sand

:

:

:

:

:

:

:

:

:

:

:

:

:

:

:

:

:

:

:

:

:

GLOSSARY OF ABBREVIATIONS AND DEFINITIONS

Thousand(s)

US dollar(s)

Percent or percentage

Associated Environmental Industries, Corp.

Above mean sea level

American Petroleum Institute

Asset Retirement Obligation(s)

Average Selling Price

ASTM International (formerly American Society for Testing and Materials)

BNSF Railway Company

John T. Boyd Company

Capital expenditures

A monetary measure that is not influenced by inflation and used to compare time periods.
Sometimes referred to as “real dollars”.

CSX Transportation

Discounted Cash Flow

A rate of return used to discount future cash flows based on the return investors expect to receive
from their investment.

Exploration and Production

Earnings before interest and taxes

Earnings before interest, taxes, depreciation, and amortization

Environmental Site Assessment

See “Proppant Sand”

JOHN T. BOYD COMPANY

    GLOSSARY OF ABBREVIATIONS AND DEFINITIONS - Continued 

    2

ft

Indicated Proppant Sand
Resource

Inferred Proppant Sand
Resource

IRR

ISO

ISP

lb

LOM

Lyntegar

:

:

:

:

:

:

:

:

Foot/feet

That part of a proppant sand resource for which quantity and quality are estimated based on
adequate geological evidence and sampling. The level of geological certainty associated with an
indicated proppant sand resource is sufficient to allow a qualified person to apply modifying
factors in sufficient detail to support mine planning and evaluation of the economic viability of the
deposit. Because an indicated proppant sand resource has a lower level of confidence than the
level of confidence of a measured proppant sand resource, an indicated proppant sand resource
may only be converted to a probable proppant sand reserve.

That part of a proppant sand resource for which quantity and quality are estimated based on
limited geological evidence and sampling. The level of geological uncertainty associated with an
inferred proppant sand resource is too high to apply relevant technical and economic factors likely
to influence the prospects of economic extraction in a manner useful for evaluation of economic
viability. Because an inferred proppant sand resource has the lowest level of geological
confidence of all proppant sand resources, which prevents the application of the modifying factors
in a manner useful for evaluation of economic viability, an inferred proppant sand resource may
not be considered when assessing the economic viability of a mining project, and may not be
converted to a proppant sand reserve.

Internal rate-of-return

International Organization for Standardization

Industrial and Specialty Products

Pound

Life-of-Mine

Lyntegar Electric Cooperative, Inc.

JOHN T. BOYD COMPANY

    GLOSSARY OF ABBREVIATIONS AND DEFINITIONS - Continued 

    3

Measured Proppant Sand
Resource

Mesh

Mineral Reserve

Mineral Resource

Modifying Factors

MSHA

MSGP

NTU
NPV

O&G

:

:

:

:

:

:

:
:

:

That part of a proppant sand resource for which quantity and quality are estimated based on
conclusive geological evidence and sampling. The level of geological certainty associated with a
measured proppant sand resource is sufficient to allow a qualified person to apply modifying
factors, as defined herein, in sufficient detail to support detailed mine planning and final
evaluation of the economic viability of the deposit. Because a measured proppant sand resource
has a higher level of confidence than the level of confidence of either an indicated proppant sand
resource or an inferred proppant sand resource, a measured proppant sand resource may be
converted to a proven proppant sand reserve or to a probable proppant sand reserve

A measurement of particle size often used in determining the size distribution of granular material.

See “Proppant Sand Reserve”

See “Proppant Sand Resource”

The factors that a qualified person must apply to indicated and measured proppant sand
resources and then evaluate to establish the economic viability of proppant sand reserves. A
qualified person must apply and evaluate modifying factors to convert measured and indicated
proppant sand resources to proven and probable proppant sand reserves. These factors include
but are not restricted to: mining; processing; infrastructure; economic; marketing; legal;
environmental compliance; plans, negotiations, or agreements with local individuals or groups;
and governmental factors. The number, type and specific characteristics of the modifying factors
applied will necessarily be a function of and depend upon the mineral, mine, property, or project.

Mine Safety and Health Administration. A division of the U.S. Department of Labor

Multi-Sector General Permit

Nephelometric turbidity units.
Net Present Value

Oil and Gas

JOHN T. BOYD COMPANY

    GLOSSARY OF ABBREVIATIONS AND DEFINITIONS - Continued 

    4

Probable Proppant Sand
Reserve

Production Stage Property

Proppant Sand

Proppant Sand Reserve

Proppant Sand Resource

Proven Proppant Sand
Reserve

PSI

PST

QP

:

:

:

:

:

:

:

:

:

The economically mineable part of an indicated and, in some cases, a measured proppant sand
resource.

A property with material extraction of proppant sand reserves.

Proppant (frac) sand is a naturally occurring, high silica content quartz sand, with grains that are
generally well rounded and exhibit high compressive strength characteristics relative to other
proppant sand. It is utilized as a prop or “proppant” in unconventional shale frac well completions.

Proppant sand reserve is an estimate of tonnage and grade or quality of indicated and measured
proppant sand resources that, in the opinion of the qualified person, can be the basis of an
economically viable project. More specifically, it is the economically mineable part of a measured
or indicated Proppant sand resource, which includes diluting materials and allowances for losses
that may occur when the material is mined or extracted.

Proppant sand resource is a concentration or occurrence of material of economic interest in or on
the Earth's crust in such form, grade or quality, and quantity that there are reasonable prospects
for economic extraction. A proppant sand resource is a reasonable estimate of mineralization,
taking into account relevant factors such as cut-off grade, likely mining dimensions, location or
continuity, that, with the assumed and justifiable technical and economic conditions, is likely to, in
whole or in part, become economically extractable. It is not merely an inventory of all
mineralization drilled or sampled.

The economically mineable part of a measured proppant sand resource which can only result
from conversion of a measured proppant sand resource.

Pounds per square inch

Petroleum Storage Tank

Qualified Person

JOHN T. BOYD COMPANY

    GLOSSARY OF ABBREVIATIONS AND DEFINITIONS - Continued 

    5

Qualified Person

:

An individual who is:

1. A mineral industry professional with at least five years of relevant experience in the type of

mineralization and type of deposit under consideration and in the specific type of activity that
person is undertaking on behalf of the registrant; and

2. An eligible member or licensee in good standing of a recognized professional organization at
the time the technical report is prepared. For an organization to be a recognized professional
organization, it must:

a. Be either:

i. An organization recognized within the mining industry as a reputable professional

association; or

ii.A board authorized by U.S. federal, state, or foreign statute to regulate professionals

in the mining, geoscience, or related field;

b. Admit eligible members primarily based on their academic qualifications and experience;
c. Establish and require compliance with professional standards of competence and ethics;
d. Require or encourage continuing professional development;
e. Have and apply disciplinary powers, including the power to suspend or expel a member

regardless of where the member practices or resides; and

f. Provide a public list of members in good standing.

Run-of-Mine. The processing feed material, including proppant sand and any inseparable waste,
excavated from the mine.

U.S. Securities and Exchange Commission

Subpart 1300 and Item 601(b)(96) of the U.S. Securities and Exchange Commission’s Regulation
S-K

Stormwater Pollution Prevention Plan

Short Ton. A unit of weight equal to 2,000 pounds

Texas Commission on Environmental Quality

U.S. Silica Company, its parent company (U.S. Silica Holdings, Inc.) and its consolidated
subsidiaries as a combined entity.

:

:

:

:

:

:

:

ROM

SEC

S-K 1300

SWPPP

Ton

TCEQ

U.S. Silica

WIP

: Work-in-progress

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JOHN T. BOYD COMPANY

 
 
1-1

1.0    EXECUTIVE SUMMARY

1.1    Introduction

Commissioned in 2018, U.S. Silica’s Lamesa Operation is an active surface mining and processing operation that produces a range

of finished proppant (frac) sand products.

BOYD prepared this technical report summary for U.S. Silica in support of their disclosure of proppant sand reserves for the

Lamesa Operation in accordance with Subpart 1300 and Item 601(b)(96) of the SEC's Regulation S-K (S-K 1300). The purpose of

this report is threefold: (1) to summarize material technical and geoscientific information for the subject mining property, (2) to

provide the conclusions of our technical assessment, and (3) to provide a statement of proppant sand resources and/or reserves for

the Lamesa Operation.

Information used in our assessment was obtained from: (1) files provided by U.S. Silica, (2) discussions with U.S. Silica personnel,

(3) records on file with regulatory agencies, (4) public sources, and (5) nonconfidential information in BOYD’s possession.

Unless otherwise noted, the effective date of the information, including estimates of proppant sand resources and reserves, is
December 31, 2022.

Weights and measurements are expressed in the US customary measurement system throughout this report.

1.2    Property Description

U.S. Silica’s Lamesa Operation is located northwest of the City of Lamesa in Dawson County, Texas. The cities of Lubbock and

Dallas, Texas, are located approximately 56 miles northeast and 312 miles east, respectively, of the Lamesa Operation. The general

location of the Lamesa Operation is provided in Figure 1.1, following this page.

The property comprises ±3,523 generally contiguous acres of surface and mineral rights wholly owned by U.S. Silica. The Lamesa
Operation’s mine offices, maintenance facilities, processing plant, loadout facilities, and tailings ponds are located on the northeast

corner of the property, while the active and future mining areas are located to the west.

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1-2

    
1-3

1.3    Geology
Most of the Lamesa property is covered by gently rolling Quaternary sheet and dune sands. Two surficial sand units have been

targeted for mining—an upper clean sand unit and an underlying clayey cover sand unit.

Exploration data indicate the clean sand unit generally consists of unconsolidated, fine- to medium-grained, well sorted and
subangular to rounded sand grains, ranging in thickness from 13 to 46 ft. The clean sand is noted as containing generally less than
10% to 15% of very fine (clay) material. The central and western extents of the Lamesa property exhibit the clean sand unit at the

surface, thinning to the east, and the unit is absent over the eastern-most third of the property. The limit of the clean sand deposit is
delineated by a clearly visible “dune line” running north to south and bisecting the subject property.

East of the dune line, the cover sand unit is present at the surface. The cover sand is also present and underlies nearly all the clean

sand west of the dune line on the Lamesa property. Geologic logs describe this unit as consisting of a clayey, hard sandstone

interval, with very fine- to medium-grained, subangular to rounded sand grains, ranging in thickness from 0 to 25 ft. The cover sand

is noted as consisting of 15% to 45% fine material due to this unit’s higher clay content.

Where covered, the sand is overlain by a negligible layer of overburden material consisting of vegetation and oversize rock. The two

sand units are generally mineable from the ground surface down to the basal red clay unit. Combined thickness of both sand units

ranges from 25 to 65 ft across the property.

1.4    Exploration
During 2017 and 2018, U.S. Silica has completed three geologic exploration campaigns in and around the Lamesa property. U.S.

Silica provided data collected from 49 drill holes completed in and around the Lamesa property that were utilized to define the
lateral extent, thickness, particle size distribution, and proppant sand characteristics of the target sand deposit.

BOYD’s audit indicates that in general: (1) U.S. Silica has performed extensive drilling and sampling work on the subject property,
(2) the work completed has been done by competent personnel, and (3) the amount of data available combined with extensive

knowledge and recent production of the Llano Estacado deposit are sufficient to confirm the thickness, lateral extents, and quality
characteristics of the Lamesa proppant sand reserves.

JOHN T. BOYD COMPANY

1-4

1.5    Proppant Sand Resources and Reserves
As shown in Table 1.1, below, U.S. Silica owns approximately 5.4 million in place tons of measured and indicated proppant sand

resources and 5.0 million in place tons of inferred proppant sand resources, exclusive of proppant sand reserves, at the Lamesa
Operation, as of December 31, 2022.

While these “additional” proppant sand resources have not been included in the Lamesa Operation’s life-of-mine (LOM) plan, they
are considered to have prospects for eventual economic extraction by virtue of their similarity—in terms of demonstrated extraction
methods and expected finished product qualities—to those converted to proppant sand reserves.

U.S. Silica’s estimated surface mineable proppant sand reserves for the Lamesa Operation total 79.6 million saleable product tons
remaining as of December 31, 2022. The proppant sand reserves are fully owned by U.S. Silica and are summarized in Table 1.2,
below.

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1-5

The Lamesa Operation has a well-established commercial history of mining, processing, and selling proppant sand products to a

variety of customers. BOYD has concluded that sufficient studies have been undertaken to enable the proppant sand resources to

be converted to proppant sand reserves based on proposed operating methods and forecasted costs and revenues.

1.6    Operations

1.6.1    Mining

Contractors are employed to conduct surface mining on the central and western portions of the Lamesa property. The Llano

Estacado sand is excavated using conventional truck and excavator methods. The negligibly thin layer of overburden is mined with

the unconsolidated sand dunes. The sand does not require drilling or blasting. A front-end loader is used to load articulated haul

trucks with disaggregated sand. The haul trucks deliver raw sand material to run-of-mine (ROM) stockpile located near processing

facilities.

Over the past four years, the operation has mined almost 20 million tons of raw sand. During late 2019 and 2020, production fell

due to the COVID-19 pandemic from roughly 4.8 million ROM tons per year to 4.2 million ROM tons. U.S. Silica’s LOM plan

forecasts mining 106.1 million ROM tons of sand at a rate of 6.1 million tons in 2023 increasing to 8.0 million by 2037 and ending in

2038.

BOYD reviewed the LOM plans for U.S. Silica’s Lamesa Operation to determine whether the plans: (1) utilize generally accepted

engineering practices, and (2) align with historical and industry norms. Based on our assessment, it is BOYD’s opinion that the

forecasted production levels for the Lamesa Operation are reasonable, logical, and consistent with typical sand mining practices in

the west Texas region and historical results achieved by U.S. Silica.

1.6.2    Processing

The Lamesa Operation’s Wet and Dry Processing Plants are located toward the eastern end of the site.

Mined ROM material from the pit arrives at the Wet Processing Plant by truck, where it is screened and washed to remove

vegetation, oversize (> 40-mesh) and fine waste (< 200-mesh) material. The remaining material is mixed with water to create a

slurry that is passed through a series of desliming cyclones and attrition scrubbers to remove clay and undersized (very fine)

particles. The deslimed material is then processed through a

JOHN T. BOYD COMPANY

1-6

series of hydrosizers, hydro-cyclones, and vacuum filters to remove excess water. The remaining “work-in-progress” (WIP) material

is stockpiled outside on a drain pad to further reduce moisture before it is recovered and enters the Dry Processing Plant. . Within

the Dry Processing Plant, the WIP sand is dried, sized and sorted. The 40/70-mesh and 100-mesh dry finished products are stored

in silos prior to loading in bulk truck for shipment to customers in the Permian Basin.

The processing operations have a nominal capacity of 6.0 million tons of finished sand per year. Based on our review, it is BOYD’s

opinion that the processing methods and existing equipment at the plant will be sufficient for the forecasted production levels over

the life of the operation.

1.6.3    Other Infrastructure

The Lamesa Operation is supported by various utilities and transportation networks needed to allow processing and transportation

of finished proppant sands.

Electricity to the Lamesa site is delivered through an above-ground network that terminates at a substation at the processing facility,

and from there electricity is distributed via several underground and above-ground powerlines.

Industrial water is recovered and recycled for reuse whenever possible. Makeup water is obtained from wells drilled on the Lamesa

site and neighboring properties. Potable water is delivered in water jugs and bottles.

Natural gas is supplied via several underground pipelines.

Tailings from processing consist generally of clays, silts, and very fine sands, which are typically disposed of in old mining pit

impoundments. The tailings ponds are currently located west of the processing plant and are designed to accommodate rejects

produced during the next several years of production. At that time, it is expected that mining will have advanced to the west, and the

then available mined pits will be used for tailings disposal.

Transportation needs are met through a well-developed road network on both paved and graded dirt roads. The Lamesa Operation

is not served by any railroads.

JOHN T. BOYD COMPANY

1-7

1.7    Financial Analysis

1.7.1    Market Analysis

U.S. Silica supplies a range of proppant sand products to major Oilfield Services

companies and Exploration and Production (E&P) companies operating in the Permian Basin. The Lamesa Operation is U.S.

Silica’s largest of two proppant sand operations in west Texas. Finished proppant sand products supplied by the Lamesa Operation

primarily consist of non-API standard 40/140-mesh and “100-mesh” (50/140-mesh) sized sand, with lesser amounts of API standard

40/70-mesh sized sand.

U.S. Silica operates in a highly competitive market that is characterized by a small number of large, national proppant sand

producers and a larger number of small, regional or local, privately-owned producers. Competition in the industry is based on: (1)

delivered price; (2) product consistency and quality; (3) supply capacity and reliability; and (4) customer service and technical

support. The Lamesa Operation’s substantial on-site product storage capacity and its strategic, in-basin location allows shipping

finished products to regional customers by truck. Since transportation costs are a significant portion of the total cost to customers of

proppant sands, development of the Lamesa, Texas plant as a regional frac sand facility in the Permian Basin allows U.S. Silica to

compete against proppant sand products being shipped from regional producers as well as from distant states like Wisconsin,

Illinois, and Missouri.

U.S. Silica’s product sales were materially impacted by the COVID-19 pandemic, with sales dropping precipitously in 2020.

However, their sales volumes and revenues have recovered substantially, and continued growth is expected over the long-term.

1.7.2    Capital and Operating Cost Estimates

The Lamesa Operation’s financial performance over the last years is summarized as follows:

• Average realization (selling price) for finished proppant sand products increased significantly from $21.85 per ton sold in 2020 to

$31.39 per ton sold in 2022.

•

Total cash cost of sales increased from $10.23 per ton sold in 2020 to $13.94 per ton sold in 2022.

• EBITDA margin increased slightly from 53.2% in 2020 to 55.6% in 2022.

• Capital expenditures totaled almost $4.2 million over the last three years, averaging $0.37 per ton sold.

Forward-looking production and unit cost estimates are based on actual past performance and subject to U.S. Silica’s customary

internal budget review and approvals

JOHN T. BOYD COMPANY

1-8

process. In BOYD’s opinion, operating volumes are well-defined and understood, as are mining and processing productivities.

The Lamesa Operation and related facilities are fully developed and should not require any near-term major capital investment to

maintain full commercial production. Historically, the timing and amount of capital expenditures has been largely discretionary and

within U.S. Silica’s control. Their budgetary allocations for sustaining and discretionary capital expenditures over the next three

years totals $2.8 million. Thereafter, capital expenditures are expected to rise yearly at a rate of 3% annually starting in 2026. BOYD

considers the near-term detailed capital expenditure schedule as presented by U.S. Silica to be reasonable and representative of

the capital necessary to operate the Lamesa Operation.

Operating cost estimates were developed based on recent actual costs and considering specific operational activity levels and cost

drivers. In the near-term, U.S. Silica expects their unit operating costs to stay relatively consistent (on an uninflated basis). As such,

the projected total cash cost of sales over the life of the mine is $13.94 per ton sold. As the operation is in a steady state, BOYD

considers the future operating cost estimates to be reasonable and appropriate.

1.7.3    Economic Analysis

An economic analysis of the Lamesa Operation was prepared in-house by U.S. Silica as part of their annual budgeting process. The

financial model forecasts future free cash flow from proppant sand production and sales over the remaining life of the Lamesa

Operation using the annual forecasts of production, sales revenues, and operating and capital costs.

JOHN T. BOYD COMPANY

Table 1.3, below, provides a summary of the estimated financial results for the remaining life of the Lamesa Operation.

1-9

Table 1.4 summarizes the results of the pre-tax and after-tax discounted cash flows (DCF) and net present value (NPV) analyses for

the Lamesa Operation.

The NPV estimate was made for purposes of confirming the economic viability of the reported proppant sand reserves and not for

purposes of valuing U.S. Silica, the Lamesa Operation, or its assets. Internal rate-of-return (IRR) and project payback were not

calculated, as there was no initial investment considered in the financial analysis presented herein.

BOYD reviewed the financial model and its inputs in detail, and opined that model provides a reasonable and accurate reflection of

the Lamesa Operation’s expected

JOHN T. BOYD COMPANY

1-10

economic performance based on the assumptions and information available at the time of our review.

1.8    Permitting Requirements

Numerous permits are required by federal and state law for mining, processing, and related activities at the Lamesa Operation,

which U.S. Silica reports are in place or pending approval. New permits or permit revisions may be necessary from time to time to

facilitate future operations. Given sufficient time and planning, U.S. Silica should be able to secure new permits, as required, to

maintain its planned operations within the context of current regulations.

U.S. Silica reports having an extensive environmental management and compliance process designed to follow or to exceed

industry standards.

Mine safety is regulated by the U.S. Department of Labor’s Mine Safety and Health Administration (MSHA). MSHA inspects the

facilities a minimum of twice yearly. U.S. Silica’s safety record compares favorably with its regional peers.

BOYD is not aware of any regulatory violation or compliance issue which would materially impact the proppant sand reserve

estimate.

1.9    Conclusions

It is BOYD’s overall conclusion that U.S. Silica’s estimates of proppant sand reserves for the Lamesa Operation, as reported herein:

(1) were prepared in conformance with accepted industry standards and practices, and (2) are reasonably and appropriately

supported by technical evaluations, which consider all relevant modifying factors.

It is BOYD’s opinion that extraction of the proppant sands reported herein is technically, legally, and economically achievable after

the consideration of potentially material modifying factors. The ability of U.S. Silica, or any mine operator, to recover all the reported

proppant sand reserves is dependent on numerous factors that are beyond the control of, and cannot be anticipated by, BOYD.

These factors include mining and geologic conditions, the capabilities of management and employees, the securing of required

approvals and permits in a timely manner, future proppant sand prices, etc. Unforeseen changes in regulations could also impact

performance.

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JOHN T. BOYD COMPANY

2-1

2.0    INTRODUCTION

2.1    Registrant

U.S. Silica is a US-based mining company headquartered in Katy, Texas. The company’s common stock is listed on the New York

Stock Exchange (NYSE:SLCA). U.S. Silica is actively engaged in the production and marketing of commercial silica sand and

performance materials (diatomaceous earth, calcium bentonite clay, calcium montmorillonite clay, and perlite products). Their whole

grain silica products are used as proppant (frac) sand for oil and natural gas recovery, and in the manufacture of glass, foundry, and

building products. U.S. Silica’s performance materials are used in: (1) filtration for foods and beverages, pharmaceuticals, and

swimming pools; (2) as additives in paint and coatings, plastics and rubber, and agriculture products; and (3) for bleaching, catalysis

and adsorption in edible oil processing, aromatics purification, and industrial and chemical applications. Additional information

regarding U.S. Silica can be found on their website: www.ussilica.com.

2.2    Terms of Reference and Purpose

U.S. Silica retained BOYD to complete an independent technical assessment of their internally-prepared proppant sand resource

and reserve estimates and supporting information for the Lamesa Operation.

BOYD prepared this technical report summary for U.S. Silica in support of their disclosure of proppant sand reserves for the

Lamesa Operation in accordance with S-K 1300. The purpose of this report is threefold: (1) to summarize material technical and

geoscientific information for the subject mining property, (2) to provide the conclusions of our technical assessment, and (3) to

provide a statement of proppant sand resources and/or reserves for the Lamesa Operation.

BOYD’s findings are based on our detailed examination of the supporting geologic and other scientific, technical, and economic

information provided by U.S. Silica, as well as our assessment of the methodology and practices applied by U.S. Silica in

formulating the estimates of proppant sand resources and reserves disclosed in this report. We did not independently estimate

proppant sand resources or reserves from first principles.

We used standard engineering and geoscience methods, or a combination of methods, that we considered to be appropriate and

necessary to establish the conclusions set forth herein. As in all aspects of mining property evaluation, there are uncertainties

JOHN T. BOYD COMPANY

2-2

inherent in the interpretation of engineering and geoscience data; therefore, our conclusions necessarily represent only informed

professional judgment.

The ability of U.S. Silica, or any mine operator, to recover all of the estimated proppant sand reserves presented in this report is

dependent on numerous factors that are beyond the control of, and cannot be anticipated by, BOYD. These factors include mining

and geologic conditions, the capabilities of management and employees, the securing of required approvals and permits in a timely

manner, future sand prices, etc. Unforeseen changes in regulations could also impact performance. Opinions presented in this

report apply to the site conditions and features as they existed at the time of BOYD’s investigations and those reasonably

foreseeable.

This report is intended for use by U.S. Silica, subject to the terms and conditions of its professional services agreement with BOYD.

We also consent to U.S. Silica filing this report as a technical report summary with the SEC pursuant to S-K 1300. Except for the

purposes legislated under US securities law, any other uses of or reliance on this report by any third party is at that party’s sole risk.

2.3    Expert Qualifications

BOYD is an independent consulting firm specializing in mining-related engineering and financial consulting services. Since 1943,

BOYD has completed over 4,000 projects in the United States and more than 60 other countries. Our full-time staff comprises

mining experts in: civil, environmental, geotechnical, and mining engineering; geology; mineral economics; and market analysis. Our

extensive experience in proppant sand resource and reserve estimation combined with our knowledge of the subject property,

provides BOYD an informed basis on which to opine on the reasonableness of the estimates provided by U.S. Silica. An overview of

BOYD can be found on our website at www.jtboyd.com.

The individuals primarily responsible for completing this technical assessment and the preparation of this report are by virtue of their

education, experience, and professional association considered qualified persons (QPs) as defined in S-K 1300.

Neither BOYD nor its staff employed in the preparation of this report have any beneficial interest in U.S. Silica, and are not insiders,

associates, or affiliates of U.S. Silica. The results of our assessment were not dependent upon any prior agreements concerning the

conclusions to be reached, nor were there any undisclosed understandings concerning any future business dealings between U.S.

Silica and BOYD. This report was

JOHN T. BOYD COMPANY

2-3

prepared in return for fees based upon agreed commercial rates, and the payment for our services was not contingent upon our

opinions regarding the project or approval of our work by U.S. Silica and its representatives.

2.4    Principal Sources of Information

Information used in this assignment was obtained from: (1) files provided by U.S. Silica, (2) discussions with U.S. Silica personnel,

(3) records on file with regulatory agencies, (4) public sources, and (5) nonconfidential information in BOYD’s possession.

The following information was provided by U.S. Silica:

• Year-end reserve statements and reports for 2021 and 2022.
• Exploration records (e.g., drilling logs and lab sheets).
• Geologic databases of lithology and sand quality.
• Computerized geologic models.
• Mapping data, with:

Land ownership boundaries.
Infrastructure locations.

-
-
- Easement and right-of-way boundaries.
- Surveyed topography (surface elevation).

• Mine plans, production schedules, and supporting data.
• Overview of processing operations and detailed flow sheets.
• Copies of mining and operating permits.
• Historical information, including:

- Production reports.
-
Financial statements.
- Product sales and pricing.

Information from sources external to BOYD and/or U.S. Silica are referenced accordingly.

The data and work papers used in the preparation of this report are on file in our offices.

2.5    Personal Inspections

A site visit and inspection of the Lamesa Operation was completed on October 26, 2022,

by BOYD’s QPs responsible for the preparation of this report. The site visit included: (1) observation of the active mining operations,

(2) a tour of the mine site’s surface infrastructure, and (3) a tour of the process plant and truck loadouts. BOYD’s representatives

were accompanied by senior U.S. Silica engineering and management

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personnel who openly and cooperatively answered questions regarding, but not limited to: site history; deposit geology; mining and

processing operations; near- and long-range mining plans; and proppant sand marketing.

2.6    Report Version

The proppant sand resources and reserves presented in this Technical Report Summary are effective as of December 31, 2022.

The effective (i.e., “as of”) date of the report is December 31, 2022.

This is the third Technical Report Summary filed by U.S. Silica for the Lamesa Operation and supersedes the following previously

filed reports:

Westward Environmental; February 2022; Technical Report Summary Lamesa Site, Dawson County, Texas.

Westward Environmental; September 2022; Technical Report Summary Lamesa Site, Dawson County, Texas.

The user of this document should ensure that this is the most recent disclosure of proppant sand resources and reserves for the

Lamesa Operation as it is no longer valid if more recent estimates have been issued.

2.7    Units of Measure

The US customary measurement system has been used throughout this report. Tons are short tons of 2,000 pounds-mass. Unless

otherwise stated, currency is expressed in US Dollars ($). Historic prices and costs are presented in nominal (unadjusted) dollars.

Future dollars values are expressed on a constant (unescalated) basis.

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3.0    PROPERTY DESCRIPTION

3.1    Location

U.S. Silica’s Lamesa Operation is a surface proppant sand mining and processing operation located 11 miles northwest of the City

of Lamesa in Dawson County, Texas. The cities of Dallas and Lubbock, Texas, are located approximately 312 miles east and 56

miles northeast, respectively, of the Lamesa Operation. Figure 1.1 (page 1-2) provided the general location of the Lamesa

Operation.

The property is contiguous with the exception of pre-existing oil production infrastructure easements for roads, storage areas,

pipelines and pump jack stations. The mine offices, maintenance facilities, processing plant, loadout facilities, and former mining pits

are located on the northeast edge of the property. Figure 3.1, on the following page, illustrates the general layout of the Lamesa

Operation.

Geographically, the Lamesa Operation’s processing plant is located at approximately 32° 48' 22.522" N latitude and 102° 7' 33.823"

W longitude.

3.2    Property Rights
The Lamesa Operation comprises approximately 3,523 acres of surface and minerals rights fully owned by U.S. Silica. The land
with mineral rights was purchased by U.S. Silica for the purposes of developing a new proppant sand mine in the Permian Basin.

3.3    Encumbrances

3.3.1    Fees and Royalties

To maintain ownership of the Lamesa Operation property, U.S. Silica must pay property taxes to the local government in Dawson

County. To BOYD’s knowledge, there are no liens against the properties.

It is BOYD’s understanding that there are no royalties, overriding or limited royalties, working interests, production payments, net

profit interests, or other mineral interests in the Lamesa Operation properties.

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3.3.2    Permitting Requirements

Mining and processing activities on the Lamesa Operation properties are regulated by several federal and state laws. As mandated

by these laws and regulations, numerous permits are required for mining, processing, and other incidental activities. U.S. Silica

reports that necessary permits are in place or applied for to support immediate operations. New permits or permit revisions may be

necessary from time to time to facilitate future operations. Given sufficient time and planning, U.S. Silica should be able to secure

new permits, as required, to maintain its planned operations within the context of the current regulations. Permitting and permitting

conditions are discussed further in Chapter 17 of this report.

In BOYD’s opinion, U.S. Silica has demonstrated their ability and cooperation to align their operating plans with any permitting

requirements that may be encountered during the normal course of business.

BOYD is not aware of any current material violations or fines imposed by regulators on the Lamesa Operation.

3.3.3    Mining Restrictions

Several man-made features have been identified in and around the Lamesa Operation which may limit the mineable areas of the

property. As of this report, these features include:

• Setbacks from neighboring properties.

• Setbacks from oil production infrastructure.

• Setbacks from existing utility corridors.

U.S. Silica has included suitable setbacks in their mining plans to avoid disturbing these areas. As such, these areas have been

excluded from the estimates of proppant sand resources and reserves presented herein.

There are no designated wetland areas or other environmentally sensitive areas which must be excluded from mining activities on

the property.

3.3.4    Other Significant Factors or Risks

To the extent known to BOYD, there are no other significant factors and risks that may affect access, title, or the right or ability to

perform work on the Lamesa Operation property that are not discussed in this report. However, the reported proppant sand

resources and reserves may be materially impacted by: U.S. Silica’s failure to comply

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with permit conditions and rules; delays in obtaining required government or other regulatory approvals or permits; U.S. Silica’s

inability to obtain such required approvals or permits; or unforeseen changes in governmental regulations.

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4.0    PHYSIOGRAPHY, ACCESSIBILITY, AND INFRASTRUCTURE

4.1    Topography, Elevation, and Vegetation

The Lamesa Operation lies within the Llano Estacado, a Southern High Plains extension of the Great Plains of North America. This

region is relatively flat, with windblown sand dunes in various locations.

Surface elevations in and around the property range from approximately 3,065 ft above mean sea-level (AMSL) near the southeast

property corner, to over 3,190 ft AMSL on the western edge of the property.

There are not any surface waters present in and around the Lamesa Operation.

Land cover in the immediate area consists predominantly of a mixture of shinnery oak, grasses, and other various scrub vegetation.

4.2    Accessibility

General access to the Lamesa Operation is via a well-developed network of paved private, county, and state roads. These roads

provide direct access to the mine and processing facilities and are generally open year-round.

4.3    Climate

Climate in and around the Lamesa Operation is characteristic for the southwest US, with four seasons ranging from mild winters to

very hot and dry summers, with generally moderate falls and springs. The average daily high temperatures typically reach above

freezing all 12 months of the year, while the low temperatures can drop below freezing during 4 months of the year. Winter

temperatures typically range from 32 degrees Fahrenheit (° F) to 71° F, while summer temperatures usually range from 68° F to 94°

F. Average annual precipitation for the area is approximately 15 to 20 inches of rain and less than 4 inches of snow.

In general, the operating season for the Lamesa Operation is year-round. Adverse weather conditions seldom limit mining,

processing, and loading operations; however, extreme weather conditions may temporarily impact operations. Periodic flooding is

possible during heavy rainfall.

4.4    Infrastructure Availability and Sources

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The Lamesa Operation lies within a rural region of western Texas and has been operating in a region dominated by the oil and gas

industry and agricultural development. The City of Lamesa has population of 8,674 and 12,456 people live in Dawson County

according to 2020 US census data.

Finished proppant sand products from the Lamesa Operation are transported to customers by bulk truck and supported by U.S.

Silica’s extensive on-site loading, storage, and handling facility.
Several regional airports are located within an hour’s drive from the Lamesa Operation, and the Midland International Airport is just

over an hour away by car.

Reliable sources of electrical power, water, supplies, and materials are readily available. Electrical power is provided to the

operation by regional utility companies. Water is supplied by neighboring private properties, surface impoundments, or water wells.

The Lamesa Operation has an abundance of recycled processing water available.

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5.0    HISTORY

5.1    Reserve Acquisition

U.S. Silica purchased the property upon which the Lamesa Operation is situated in July 2017 from the Medlin Ranch. U.S. Silica

made the purchase after completing an initial reconnaissance-level exploration campaign in March and April 2017.

U.S. Silica is the first owner to explore for and mine proppant sand from the property. Prior to U.S. Silica’s purchase, the property

remained relatively undeveloped aside from sparse agricultural activity located in the far southeast corner of the property and

various oil and gas wells and related infrastructure.

5.2    Mine Development
The Lamesa property was purchased by U.S. Silica as a source of proppant sand to service the booming oil and gas industry in the

Permian Basin of west Texas. Prior to the development of proppant sand mining and processing operations in West Texas, nearly all
proppant sand was imported from other out-of-state producing regions. In order to lower operational costs, the oil and gas industry
began looking for cheaper (i.e., local) sources of proppant sand. U.S. Silica has actively developed several proppant sand
operations in west Texas, including the Lamesa Operation, to serve this market.

U.S. Silica began construction of the processing plant shortly after purchasing the property. First sales of finished proppant sand
from the Lamesa Operation were made in mid-2018.

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6.0    GEOLOGICAL SETTING, MINERALIZATION, AND DEPOSIT

6.1    Regional Geology

The Lamesa Operation is located within the Llano Estacado, situated in the Texas High Plains. This region comprises the southern-

most portion of the Great Plains, which extends into northeastern New Mexico and northwestern Texas. The Llano Estacado forms

a vast elevated plain (high mesa) that is almost completely covered with sand deposits of various types. In the region, the ground

surface is covered by windblown sheet sands and active sand dunes reaching heights of almost 45 ft.

The Lamesa Operation is also located near the north-central portion of the Permian Basin, which is well known for its long-

producing petroleum and natural gas fields. While the subject of this report concentrates on the surficial geology (sand deposits) of

west Texas, the Lamesa Operation currently sells its proppant sand products to the oil and gas producers working in the Permian

Basin.

6.2    Local Geology

6.2.1    General Stratigraphy

Surficial geologic units overlying the area in and around the Lamesa Operation are predominantly comprised of undifferentiated

Quaternary Age unconsolidated deposits, ranging from aeolian (windblown) sheet sands and dunes to alluvial sands, silts, clays,

and caliche. Geologic mapping shows additional surficial stratigraphic units present in the vicinity of the project; however, the

surface geology of the Lamesa Property is primarily comprised of these aeolian sand deposits.

A generalized stratigraphic chart of the geologic units in Dawson County, Texas is presented in Figure 6.1.

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The following text discusses the strata encountered in and around the Lamesa Operation in ascending depositional order.

Ogallala Formation

The Ogallala Formation is predominantly comprised of weakly cemented to unconsolidated fine- to medium-grained sands, which

may be silty and calcareous in places. A caliche caprock is frequently exhibited, which resists weathering and forms ledges.

Thickness of this formation has been recorded up to 550 ft.

Blackwater Draw Formation

The Blackwater Draw Formation covers a majority of the surface of Dawson County. While not clearly present on the surface at the

Lamesa Operation, the Blackwater Draw Formation is predominantly comprised of fine- to medium-grained sand that is silty,

calcareous, and locally clayey. Caliche nodules may be present, and deposition is noted as being massive; however, the unit

generally is found to be less than 25 ft thick.

Quaternary Sheet and Dune Sands

Most of the subject property is covered by Quaternary sheet and dune sands generally consisting of fine- to medium-grained quartz

sand grains, mixed with varying degrees of clays and silts. Exploration completed on the Lamesa Property indicates two surficial

sand units being present, an upper clean sand unit and an underlying clayey cover sand unit.

General geologic descriptions from the Dawson County area also indicate that some local Quaternary deposits may include gravel

or be locally indurated with calcium carbonate (caliche). These deposits are the result of various geologic processes during

deposition, such as the formation of levees, point bars, stream channels, alluvial fans, and terrace or playa deposits.

6.2.2    Structural Geology

The structural features of the Quaternary sands in and around the Lamesa Operation are relatively non-descript. While the unit

exhibits variable thickness over the area, it is unaffected by folding or faulting. Underlying the surficial sand units is a red clay basal

unit, which defines the limit of the mineable surface sand deposits. Due to the lack of structural features encountered, there are no

know geological features that are believed to materially affect a proppant sand mining operation in the immediate area; as such, the

deposit is considered to be of low geologic complexity.

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6.3    Property Geology

As described above, surficial geologic strata at the Lamesa Operation are predominantly comprised of aeolian (windblown) sand

deposits. There is not any discernable overburden material present except for sparse areas of vegetation and roots, which are

easily removed during early phases of the processing operations. Figure 6.2, following this page, provides a map of the sand

thickness. A cross-section through the deposit is provided in Figure 6.3.

The surface sheet and dune sands deposited on the subject property consist of two distinct intervals of mineable sand: 1) an upper

“clean sand” unit, and 2) a lower “cover sand” unit. Underlying the surface sand deposits is a hard, red clay basal unit, commonly

referred to as hardpan.

Exploration data suggest the clean sand unit generally consists of unconsolidated, fine- to medium-grained, well sorted and

subangular to rounded sand grains. Thickness of this unit ranges from 13 to 46 ft. The clean sand is noted as containing generally

less than 10% to 15% very fine (clay) material. The central and western extents of the Lamesa Property exhibit the clean sand unit

at the surface, thinning to the east, and is absent over the eastern-most third of the property. The limit of the clean sand deposit is

delineated by a clearly visible “dune line” running north to south and bisecting the subject property.

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East of the dune line, the cover sand unit is present at the surface. The cover sand is also present and underlies nearly all the clean
sand west of the dune line on the Lamesa property. Geologic logs describe this unit as consisting of a clayey, hard sandstone
interval, with very fine- to medium-grained, subangular to rounded sand grains, and
ranging in thickness from 0 to 25 ft. The cover sand is noted as consisting of 15% to 45% fine material due to the higher clay

content.

The two sand units are generally mineable from the ground surface down to the basal red clay unit. Combined thickness of both

sand units ranges from 25 to 65 ft across the property.

The sand mined at the Lamesa Operation is processed to produce proppant sand. Proppant sand is a naturally occurring, high silica

content quartz sand, with grains that are generally well-rounded. The main difference between proppant sand and other sands is

that proppant sand grains are relatively pure in composition, consisting almost entirely of quartz; other sands have numerous

impurities that may be cemented to the quartz grains. The pure quartz composition of proppant sand grains, along with being well-

rounded and spherical in shape, gives these sands the characteristics (crush strength, high acid solubility, low turbidity) that are

sought after by oil and gas producers for use in developing wells.

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7.0    EXPLORATION DATA

7.1    Background

In developing the Lamesa Operation, U.S. Silica has completed three separate geologic exploration campaigns. Records from these

campaigns were provided and comprise the primary data used in the evaluation of the proppant sand resources. A total of 49 drill

holes (totaling 2,268 ft of drilling) are distributed across the property and results have been compiled into a database. Maps

illustrating the extents of the sand deposit, electronic copies of drilling and sampling logs, as well as laboratory testing summaries,

were provided for our review.

7.2    Exploration Procedures

U.S. Silica provided BOYD with various information, including exploration reports and internal guidelines, regarding drilling,

sampling, preparing, and testing procedures utilized during the three exploration campaigns conducted on the Lamesa Operation.

7.2.1    Drilling

To date, U.S. Silica has performed three drilling campaigns on the Lamesa property. All of these campaigns were completed by

third-party contractors using rotosonic (sonic drilling) equipment. Sonic drilling is an advanced drilling technique that is widely

accepted as one of the best methods to recover core when exploring unconsolidated sand deposits.

Phase 1 Exploration Campaign

Prior to purchasing the property, U.S. Silica completed a reconnaissance-level exploration campaign in March 2017 with the aim of

evaluating the quantity and quality of the dune sand deposit on the property,

Drilling was planned and supervised by U.S. Silica’s Mine Planning Department, who also conducted core logging and sampling in

the field. Cascade Environmental, LLC performed the drilling and a total of five rotosonic holes were completed. The drill holes were

laid out in a general east to west trending line across an area of the property with visible sand dunes.

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Phase 2 Exploration Campaign

An infill drilling campaign, consisting of 11 rotosonic drill holes, was planned and completed in April 2017 on the Lamesa property.

The campaign was designed to support detailed mine planning and the estimation proppant sand reserves.

A geologist from Summit Envirosolutions, Inc. was engaged to log and sample core and supervise this phase of exploration work.

Associated Environmental Industries, Corp. (AEI) performed the drilling.

After the completion of this exploration campaign, U.S. Silica prepared an initial proppant sand reserve estimate for the Lamesa

Operation, and subsequently finalized the purchase of the property in July 2017.

Phase 3 Exploration Campaign

In September 2018, U.S. Silica’s Mine Planning Department completed a larger exploration campaign. This exploration campaign

was designed to increase confidence in the delineation (i.e., areal extent and thickness) of the sand deposit, and identify areas with

preferred sand qualities.

AEI was contracted to complete the 33 rotosonic drill holes. An independent geologic consultant, Geological Consulting Services,

Inc., was engaged to supervise drilling activities, and to log and sample the recovered core.

7.2.2    Sampling Procedures

Sampling procedures indicate that after a drill hole's recovered core was measured and geologically logged, the core was boxed

and transported to U.S. Silica’s Berkeley Springs, West Virginia, laboratory. At the lab, separate homogenous and representative

composite samples were taken of the clean sand and cover sand units for analysis.

U.S. Silica maintained control of exploration core samples throughout the entirety of each drilling campaign, which included: (1)

logging and boxing of recovered cores in the field, (2) transportation and delivery of core samples to their internal laboratories, and

(3) performing preparation and analyses on each of the samples.

Available testing results were reviewed by BOYD during our assessment. Our review of the preceding field and sampling

procedures showed that the general description and sampling work were conducted to appropriate standards. Based on the stated

standards, both in the field and in the laboratory, BOYD concludes that the sample preparation and

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analytical procedures were adequate for the purposes of evaluating and estimating proppant sand resources and reserves at the

Lamesa Operation.

7.2.3    Sand Testing
Samples obtained from the exploration campaigns were taken to the company’s Berkeley Springs laboratory, where they were

inventoried and then prepared for analyses. Samples were split and prepared following standardized company procedures (i.e.,

U.S. Silica’s ISO 9001 Quality System of Corporate Analytical Procedures) to ensure analytical consistency throughout each of the

various exploration campaigns. These procedures are designed to closely match the operational capabilities of the Lamesa

Operation’s processing plant.

Preparation of each sample consisted of initially splitting the recovered core in half. One half of the core is placed back into the core

boxes which are then stored for archival purposes, while the other half of the core is further prepared and processed for lab testing

purposes.

Analytical samples were crushed, quartered, and mixed to create a uniform and representative composite sample of the core

interval, and then the composite sample was divided into appropriately sized samples, depending on the type and amount of testing

to be performed. The sample is then run through various crushing techniques to disaggregate the sand grains and fine materials as

much as possible before beginning the washing and scrubbing procedures.

After splitting, the sample is dried, and an approximately 1,500-gram split is obtained. The sample split is washed through a 200-

mesh sieve to remove slimes, before being dried and reweighed to measure the recovery of plus-200-mesh material. The dried

sample is then run through a 16-mesh sieve to simulate the scalping procedure in the plant to remove the “coarse waste” sized

particles. The remaining material is then approximately equivalent to the material that would typically be washed in the wet

processing plant. This remaining material is weighed and labeled as a prepared “washed sample”.

The washed sample is further prepared by simulating the wet processing plant conditions, which consist of placing the sample into

scrubbers for three minutes, rinsing and decanting, and then drying to arrive at a “scrubbed sample”, which represents material that

would be output from the wet processing plant. The scrubbed samples are then dried and prepared for API RP 19C/ISO-13503-2

standard testing for proppant materials.

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7.2.4    Other Exploration Methods

There were not any other methods of exploration (such as airborne or ground geophysical surveys) reported for the Lamesa

Operation.

7.3    Exploration Results

7.3.1    Summary of Exploration

Exploration work to date includes a total of 49 drill holes completed in and around the Lamesa property, through the course of three

separate exploration campaigns. The overall drill hole spacing exhibited across a majority of the Lamesa Operation ranges from

approximately 1,000 to 1,500 ft. The distribution of these drill holes is illustrated on Figure 7.1, following this page.

Data collected as a result of completing these drilling campaigns confirm the generally uniform nature of the deposit underlying the

Lamesa property and supports the general interpretation of the sand deposit thickness, as illustrated in Figure 6.2 (page 6-4).

Information provided from the exploration campaigns indicates U.S. Silica identified two separate sand intervals at Lamesa: 1) an
“upper clean sand” unit, which covers the surface of the western and central portions of the property, and 2) a “lower cover sand”
unit, found on the surface of the eastern portion of the property and underlying nearly all of the clean sand unit.

7.3.2    Sand Quality
The Lamesa Operation produces two varieties of proppant sand for use in local oil and gas applications: a 40/70-mesh proppant

sand product, and a 100-mesh proppant sand product. U.S. Silica reportedly performs testing at their laboratories for API/ISO

specifications.

Historically, API RP 19C/ISO 13503-2 proppant sand characteristics were strictly adhered to in order to determine the suitability of a

sand product for use during fracking stages of oil and gas well development. Over time, these specifications have become merely

guidelines, and the suitability of a proppant sand product is now ultimately determined by customers, who will typically perform their

own sample testing of the products that they purchase to determine if they meet their internal specifications.

BOYD notes that U.S. Silica has demonstrated continued commercial success in producing and marketing the finished proppant

sand products; as such, it is BOYD’s

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opinion that sand quality data provided are representative of the mined deposit and are considered suitable for the estimation of

proppant sand resources and reserves.

7.3.3    Grain Size Distribution

Grain size distribution was analyzed according to API RP 19C/ISO 13503-2, Section 6.

A table of weighted average grain size distribution of the in-situ sand deposit, based on laboratory testing results, is shown in Table

7.1, below.

The preceding table highlights the relative fineness of the sand found at the Lamesa Operation, indicating a majority of the sand

particles are concentrated between the “passing 40-mesh” and “retained 140-mesh” size fraction. Accordingly, the predominant

marketable proppant sand product consists of the 40/140-mesh sand.

7.3.4    Proppant Sand Quality

Samples gathered during exploration work were prepared into composite product-size samples by U.S. Silica’s internal laboratory,

and sent to an third-party laboratory (Prop Tester, Inc.) in Cyprus, Texas for analysis of the following API RP19C/ ISO 13503-2

proppant sand characteristics.

Grain Shape (Sphericity and Roundness)

Grain shape is defined under API RP19C/ ISO 13503-2, Section 7. Under this standard, recommended sphericity and roundness

values for proppants are 0.6 or greater. As part of the grain shape analysis, the presence of grain clusters (weakly cemented grain

aggregates) and their approximate proportion in the sample are reported.

Crush Resistance

Crush resistance is a key test that determines the amount of pressure a sand grain can withstand under laboratory conditions for a

two-minute duration. It is analyzed according to API RP19C/ ISO 13503-2, Section 11. Under this standard, the highest stress level

(psi) in which the proppant produces no more than 10% crushed fine material is rounded down to the nearest 1,000 psi and

reported as the “K-value” of the material.

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Acid Solubility

Acid solubility was analyzed according to API RP19C/ ISO 13503-2, Section 8. Under this standard, 5 grams of sand is treated with
°
100 milliliters of 12:3 hydrochloric acid to hydrofluoric acid at 150  F for 30 minutes. The recommended maximum acid solubility for

proppants in the 40/70 size range and finer is 3.0%.

Turbidity

Turbidity was analyzed according to API RP19C/ ISO 13503-2, Section 9. Under this standard, the suggested maximum frac sand

turbidity should be equal to or less than 250 nephelometric turbidity units (NTU).

Results from these analyses are shown below in Table 7.2:

The composite sample testing suggests the Lamesa Operation can produce proppant sands which meet minimum API/ISO

recommended specifications. Moreover, U.S. Silica has a demonstrated commercial success producing and selling proppant sand

to Permian Basin oil and gas producers, where ultimately the sand has been shown to meet customer specifications.

7.4    Data Verification

For purposes of this report, BOYD did not verify historic drill hole data by conducting independent drilling. It is customary in

preparing similar mining resource and reserve estimates to accept basic drilling and sample quality data as provided by the client,

subject to the reported results being judged representative and reasonable.

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BOYD’s efforts to judge the appropriateness and reasonability of the source exploration data included reviewing representative

samples of provided drilling logs, sampling procedures, sand quality testing results, and discussing aspects of developing the

Lamesa Operation with U.S. Silica personnel during our site visit. Reviewed drilling records were compared with their corresponding

database records for transcription errors; of which none were found. Lithologic and sand quality data points were compared via

visual and statistical inspection with geologic mapping and cross-sections.

7.5    Adequacy of Exploration and Sampling

BOYD’s review of the reported methodologies and procedures indicate the exploration data obtained and utilized by U.S. Silica for

the Lamesa site were: (1) carefully and professionally collected, prepared, and documented, (2) conform with general industry

standards, and (3) are appropriate for use of evaluating and estimating proppant sand resources and reserves. Similarly, BOYD’s

review of testing data provided by U.S. Silica suggests that the analyses completed are generally appropriate to determine proppant

sand characteristics and determine the subsequent quality of finished proppant sand products. As such, it is BOYD’s opinion that

the exploration and sampling data are suitable for use in the estimation of proppant sand resources and reserves for the Lamesa

Operation.

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8.0    SAMPLE PREPARATION, ANALYSIS, AND SECURITY

The reader is referred to Sections 7.3 and 7.4 of this report for details regarding sample preparation, analysis, and security.

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9.0    DATA VERIFICATION

BOYD, by way of the data verification processes described in various sections of this report, has used only that data deemed by the
QPs to have been generated with proper industry standard procedures, were accurately transcribed from the original source and

were suitable to be used for the purpose of preparing estimates of proppant sand resources and reserves.

BOYD’s subject-specific data verification efforts and our conclusions arising therefrom are discussed in the following sections of this
report:

Based on our review, it is BOYD’s overall conclusion that the information made available to us at the time of this report is
representative and reliable for use in estimating the proppant sand resources and reserves of the Lamesa Operation.

BOYD is not aware of any other limitations on nor failure to conduct appropriate data verification.

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10.0    MINERAL PROCESSING AND METALLURGICAL TESTING

Please refer to Chapter 7 for information regarding grain size distribution and proppant sand characteristics testing.

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11.0    PROPPANT SAND RESOURCE ESTIMATE

11.1    Applicable Standards and Definitions

Unless noted, proppant sand resource estimates disclosed herein are done so in accordance with the standards and definitions

provided by S-K 1300. It should be noted that BOYD considers the terms “mineral” and “proppant sand” to be generally

interchangeable within the relevant sections of S-K 1300.

Estimates of mineral resources are always subject to a degree of uncertainty. The level of confidence that can be applied to a

particular estimate is a function of, among other things: the amount, quality, and completeness of exploration data; the geological

complexity of the deposit; and economic, legal, social, and environmental factors associated with mining the resource. By

assignment, BOYD used the definitions provided in S-K 1300 to describe the varying degree of certainty associated with the

estimates reported herein.

The definition of mineral resource provided by S-K 1300 is:

Mineral resource is a concentration or occurrence of material of economic interest in or on the Earth's crust in such form,
grade or quality, and quantity that there are reasonable prospects for economic extraction. A mineral resource is a
reasonable estimate of mineralization, taking into account relevant factors such as cut-off grade, likely mining dimensions,
location or continuity, that, with the assumed and justifiable technical and economic conditions, is likely to, in whole or in part,
become economically extractable. It is not merely an inventory of all mineralization drilled or sampled.

Estimates of mineral resources are subdivided to reflect different levels of geological confidence into measured (highest geologic

assurance), indicated, and inferred (lowest geologic assurance). Please refer to the Glossary of Abbreviations and Definitions for

the meanings ascribed to these terms.

JOHN T. BOYD COMPANY

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11.2    Proppant Sand Resources

11.2.1    Methodology

Based on provided information, U.S. Silica’s geologic modeling and proppant sand resource estimation techniques generally consist

of following:

1. The top and bottom elevations of the mineable proppant sand interval is interpreted from drill hole records and sand particle size
analyses. As the sands mined at the Lamesa Operation are present at the surface, no overburden material is included in the
geologic model. Strata below the sand unit—generally, the red clay basal unit, are considered waste.

2.

Interpreted drill hole records are compiled and validated. Strata thicknesses are aggregated, and sand particle size analyses of
the sand unit are composited for each data point. The compiled drill hole data are imported into GEOVIA Surpac™ geologic
modeling and mine planning software.

3. A geologic block model of the deposit is developed using industry standard stratigraphic modeling methods. The geologic model

delineates the top and bottom of the mineable sand horizon.

4. Contiguous regions of mineable sand are outlined (applying criteria discussed below in Section 11.2.2), and LOM pit shells are

created.

5. Estimates of in-place mineable sand volumes are derived from the LOM pit shells and recent topographic (surface elevation)

surveys.

6. An in-place dry density of 100 pounds per cubic foot is used to convert the in-place sand volumes to in-place sand tons.

11.2.2    Estimation Criteria

Development of the proppant sand resource estimate for the Lamesa Operation assumes mining and processing methods and

equipment which have been utilized successfully at the site for decades.

The target surface sheet and dune sand mining horizon at U.S. Silica’s Lamesa Operation is manifested as continuous, low rolling

sand dunes with relatively consistent depth, thickness, and quality. The high-quality sand is easily distinguished from the underlying

clay unit, aiding in the interpretation of the mineable horizon. Generally, all of the sand unit is mined and sold under various product

specifications. Based on the uniformity of the sand deposit being mined, cut-off grade, strip ratios, and other typical mining factors

do not define economic mineability. Production of proppant sand is driven by market demand and production can be modified in

response to that demand. As such, the application of minimum mining thicknesses, maximum stripping ratios (the ratio of waste to

sand excavated), or cut-off grades is not generally considered in the estimation of proppant sand resources for the Lamesa

Operation.

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The limits of the proppant sand resources are constrained to those portions of the interpreted sand deposit that:

• Are reasonably defined by available drilling and sampling data.

• Contain products that meet generally accepted specifications.

• Honor any legal mining constraints (e.g., property boundaries, environmental setbacks, utility and infrastructure setbacks, etc.).

• Adhere to physical mining constraints.

• Contain products that can be sold at a profit (i.e., be economic).

U.S. Silica applied the following offsets to define the proppant sand resource boundaries for the Lamesa Operation:

•
•
•

300-ft x 300-ft buffer around a single active pumpjack on the property.
100-ft offsets from neighboring property boundaries.
200-ft right-of-ways around roadways, oil and gas pipelines, and utility corridors.

The pits shells which constrain the estimated proppant sand resources utilized overall wall slope of 3:1 (horizonal to vertical) in

unconsolidated sand. There were not any other pit design criteria employed.

Proppant sand resources for the Lamesa Operation are assessed for reasonable prospects for eventual economic extraction by

reporting: (1) only those resources which have been subsequently converted to proppant sand reserves after the application of all

material modifying factors, or (2) those resources which have similar characteristics (i.e., mining conditions, and expected product

yields and qualities) to those converted to proppant sand reserves.

BOYD has reviewed the criteria employed by U.S. Silica in developing their estimates of proppant sand resources. The parameters

are supported by historical results and align with those employed at similar operations. As such, it is BOYD’s opinion that the stated

criteria are reasonable and appropriate for the estimation of proppant sand resources at the Lamesa Operation.

11.2.3    Classification

Geologic assuredness is established by the availability of both structural (thickness and elevation) and particle size distribution for

the proppant sand. Classification is generally based on the concentration or spacing of exploration data, geological understanding,

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continuity of mineralization relative to the style of mineralization, and uncertainty with the exploration data.

Table 11.1 provides the general criteria employed in the classification of the proppant sand resources.

Extrapolation or projection of resources in any category beyond any data point does not

exceed half the point spacing distance.

BOYD reviewed the classification criteria employed by U.S. Silica with regards to data density, data quality, geological continuity

and/or complexity, and estimation quality. The surficial sand dune deposit on the Lamesa property is of low geologic complexity. We

believe these criteria appropriately reflect their implied levels of geologic assurance with respect to the estimation of proppant sand

resources..

Mineable sand resources on the property are well-defined throughout all areas of the mine plan. Observed drill hole spacing

averages approximately 1,000 ft through a majority of the active mining area, with future mining areas exhibiting a general drill hole

spacing averaging approximately 1,000 ft to 2,500 ft.

JOHN T. BOYD COMPANY

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11.2.4    Proppant Sand Resource Estimate

Resource estimates of in-place proppant sand at the Lamesa Operation as of December 31, 2022, reported by U.S. Silica are

shown in Table 11.2 below.

As shown, U.S. Silica controls approximately 117 million in-place tons of measured and indicated proppant sand resources,

inclusive of proppant sand reserves. In addition, they control approximately 5 million in-place tons of inferred proppant sand

resources. Proppant sand resources are not proppant sand reserves and do not have demonstrated economic viability.

The proppant sand resources shown under the “Planned” column of Table 11.2 include only those in-place tons which are included

in U.S. Silica’s LOM plan for the Lamesa Operation and therefore considered for conversion to proppant sand reserves. The

proppant sand resources shown under the “Additional” column of Table 11.2 have not been included in the LOM plan and are

considered exclusive of (i.e., “in addition to”) the reported proppant sand reserves. These “Additional” proppant sand resources are

considered to have prospects for eventual economic extraction by virtue of their similarity, in terms of demonstrated extraction

methods and expected finished product qualities, to those converted to proppant sand reserves. However, further studies are

required to convert the “Additional” proppant sand resources to proppant sand reserves.

11.2.5    Validation

BOYD was provided with U.S. Silica’s exploration data, geologic models, and volumetric estimates. We have reviewed this

information, on a representative basis, by:

• Verifying the accuracy of geologic model inputs by comparison with drilling logs and laboratory reports.

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• Comparing the geologic model with compiled drilling data.

• Preparing a stratigraphic grid model of the sand unit and independently estimating pit shell volumes.

It is BOYD’s opinion that the geologic model is representative of the informing data and that the data are of sufficient quality to

support the proppant sand resources estimate provided herein. Furthermore, it is our opinion that the resources estimation methods

and criteria employed are both appropriate and reasonable for the deposit type and proposed extraction methods.

BOYD is not aware of any technical, legal, economic, or other relevant factors that could materially affect the silica sand resource

estimate. The accuracy of silica sand resource estimate is, in part, a function of the quality and quantity of available data and of

engineering and geological interpretation and judgment. Given the data available at the time this report was prepared, the estimates

presented herein are considered reasonable. However, they should be accepted with the understanding that additional data and

analysis available after the date of the estimate may result in a change to the current estimate. These revisions may be material.

There is no guarantee that all or any part of the estimated resources will be recoverable.

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12.0    PROPPANT SAND RESERVE ESTIMATE

12.1    Applicable Standards and Definitions

Unless noted, proppant sand reserve estimates disclosed herein are done so in accordance with the standards and definitions

provided by S-K 1300. It should be noted that BOYD considers the terms “mineral” and “proppant sand” to be generally

interchangeable within the relevant sections of S-K 1300.

Estimates of mineral reserves are always subject to a degree of uncertainty. The level of confidence that can be applied to a

particular estimate is a function of, among other things: the amount, quality, and completeness of exploration data; the geological

complexity of the deposit; and economic, legal, social, and environmental factors associated with mining the reserve. By

assignment, BOYD used the definitions provided in S-K 1300 to describe the varying degree of certainty associated with the

estimates reported herein.

The definition of mineral reserve provided by S-K 1300 is:

Mineral reserve is an estimate of tonnage and grade or quality of indicated and measured mineral resources that, in the
opinion of the qualified person, can be the basis of an economically viable project. More specifically, it is the economically
mineable part of a measured or indicated mineral resource, which includes diluting materials and allowances for losses that
may occur when the material is mined or extracted.

Estimates of mineral reserves are subdivided to reflect geologic confidence, and potential uncertainties in the modifying factors, into

proven (highest assurance) and probable. Please refer to the Glossary of Abbreviations and Definitions for the meanings ascribed

to these terms.

JOHN T. BOYD COMPANY

Figure 12.1, below, illustrates the relationship between mineral resources and mineral reserves.

12-2

Figure 12.1: Relationship Between Mineral Resources and Mineral Reserves

By industry convention, proppant sand reserves are presented on two bases: mineable and saleable. Mineable reserves represent

the ROM tonnage available for excavation and processing. Saleable reserves represent the tonnage of finished proppant sand

available for sale after processing the mineable reserves.

12.2    Proppant Sand Reserves

12.2.1    Methodology

Estimates of proppant sand reserves for the Lamesa Operation are derived contemporaneously with estimates of proppant sand

resources. The Lamesa Operation utilizes commercially proven mining and processing methods to extract and process proppant

sand from the subject property. The operation’s production plans are revised periodically to assure that the conversion of in-place

sand to saleable product are: (1) in reasonable conformity with present and recent historical operational performance, and (2)

reflective of expected mining and processing operations.

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To derive estimates of mineable tons and saleable product tons (i.e., proven and probable proppant sand reserves), the following

modifying factors were applied to the in-place measured and indicated proppant sand resources underlying the respective mine plan

areas:

• A 95% mining recovery factor, which assumes that 5% of the mineable (in-place) proppant sand resource will not be recovered
for various reasons. Applying this recovery factor to the in-place resource results in the estimated ROM sand tonnage (i.e., the
mineable proppant sand reserves) that will be delivered to the wet process plant.

• An overall 75% processing yield. This factor accounts for removal of out-sized (i.e., larger than 20-mesh and smaller than 140-

mesh) sand and losses in the wet and dry processing plants due to minor inefficiencies.

The overall product yield (after mining and processing losses) for the Lamesa Operation is estimated at approximately 71.3%. That

is, for every 100 tons of in-place proppant sand, approximately 71 tons will be recovered and sold as product. Mining recovery and

processing yield factors are derived from historical operating results.

Economic availability of the proppant sand reserves is established by the financial analysis presented in Chapter 19. A long-range

average selling price of $23.90 per product ton has been used to estimate proppant sand reserves for the Lamesa Operation.

12.2.2    Classification

Proven and probable proppant sand reserves are derived from measured and indicated proppant sand resources, respectively, in

accordance with S-K 1300. BOYD is satisfied that the stated proppant sand reserve classification reflects the outcome of technical

and economic studies. Figure 12.2, on the following page, illustrates the classification of the proppant sand resources and reserves

at the Lamesa Operation.

JOHN T. BOYD COMPANY

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12.2.3    Proppant Sand Reserve Estimate

U.S. Silica’s estimated surface mineable proppant sand reserves for the Lamesa Operation total 79.6 million saleable product tons,

as of December 31, 2022. The proppant sand reserves reported in Table 12.1, below, are based on the approved LOM plan which,

in BOYD’s opinion, is technically achievable and economically viable after the consideration of all material modifying factors.

All of the reported proppant sand reserves are wholly owned by U.S. Silica.

The proppant sand reserves of the Lamesa Operation are well-explored and defined. It is our conclusion that almost 87% of the

stated reserves can be classified in the proven reliability category (the highest level of assurance) with the remainder classified as

probable. Given the geologic uniformity and history of mining the proppant sand on the Lamesa Operation properties, it is

reasonable to assume that the small portion of probable reserves will be converted to proven reserves upon completion of additional

exploration and testing.

The Lamesa Operation has a well-established history of mining, processing, and selling proppant sand products into various

markets. BOYD has assessed that sufficient studies have been undertaken to enable the proppant sand resources to be converted

to proppant sand reserves based on current and proposed operating methods and practices. Changes in the factors and

assumptions employed in these studies may materially affect the silica proppant reserve estimate.

The extent to which the proppant sand reserves may be affected by any known geological, operational, environmental, permitting,

legal, title, variation, socio-economic, marketing, political, or other relevant issues has been reviewed as warranted. It is the opinion

of BOYD that U.S. Silica has appropriately mitigated, or has the operational acumen to mitigate, the risks associated with these

factors. BOYD is not aware of any

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additional risks that could materially affect the development of the proppant sand reserves.

Based on our independent review, we have a high degree of confidence that the estimates shown in this report accurately represent

the available proppant sand reserves controlled by U.S. Silica, as of December 31, 2022.

12.2.4    Reconciliation with Previous Estimates

When comparing U.S. Silica’s proppant sand reserve estimates as of December 31, 2022, with the estimates presented  for

1

December 31, 2021, we note a net increase of approximately 13.6 million mineable tons resulting from: (1) depletion due to mining

of approximately 5.9 million mineable tons, and (2) revisions to mine plans resulting in increases of approximately 19.5 million

mineable tons. BOYD does not consider these adjustments, either individually or combined, to represent material changes to the

proppant sand reserves of the Lamesa Operation.

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1
 U.S. Silica did not present reserves on a Saleable Tons basis for the 2021 financial year.

JOHN T. BOYD COMPANY

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13.0    MINING METHODS

13.1    Mining Operations

The sheet sands and sand dunes in and around the Lamesa Operation are loosely consolidated and overlain by minimal

overburden; characteristics which favor conventional surface mining techniques. Since the target sands formation does not extend

below the water table, the quarry is ‘dry-mined’ using truck and excavator mining methods. Mining occurs in a series of benches

arranged in a stair-like fashion to recover sand from the top of the formation (in elevation) down to the lowest practical elevation

(generally 1 to 2 ft above the basal red clay unit).

Since the overburden is very thin, it is not stripped prior to sand excavation. Any vegetation, oversize material or clay that is present

is removed at the processing plant using screens and scrubbers. Oversize material and vegetation are stored at the dry tailings

stockpile for use in future reclamation.

Drilling and blasting are not required for the loosely consolidated sand. A front-end loader is used to load the excavated ROM sand

into trucks which transport the sand to a ROM stockpile near the wet process plant. Usually, the sand horizon is mined in a single 25

ft vertical bench. If the depth of the deposit exceeds 25 ft, a second lower bench is mined down to the top of the clay rich zone. The

ROM sand recovered from these two benches are blended at the wet feed plant stockpile to maximize sand recovery. Figure 13.1,

below, shows the loading operations in the Lamesa mine.

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These surface mining techniques have been utilized at the Lamesa Operation since it began production in 2018. The mining

operations are typically conducted year-round.

13.2     Mine Equipment and Staffing

13.2.1     Mine Equipment

An independent contractor conducts the mining operation and owns and operates the mobile equipment fleet, which includes:

• Caterpillar 992 Front End Loader.
Two Caterpillar 349F Excavators.
•
Two Caterpillar static haul trucks and 8 Volvo articulated haul trucks.
•
• Caterpillar D8T Dozer.
• Water Truck and other ancillary equipment.

Regular and major repair maintenance is the responsibility of the contractor. Currently the contractor is responsible for delivering up

to 715,000 tons of ROM sand per month to the plant.

If maintained in good condition, the mobile equipment fleet should be capable of achieving production levels required by the LOM

plan.

13.2.2     Staffing

The Lamesa Operation is staffed by 150 hourly and salaried personnel. A breakdown of employees by classification is provided in

Table 13.1.

Except for a drop in employment in 2020 and 2021 (attributed to poor market conditions during the COVID-19 pandemic), the trend

in staffing levels across the Lamesa Operation has been increasing. The workforce can be expanded or reduced based on market

and seasonal demands.

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13.3     Engineering and Planning

The primary mine planning consideration is the safe, economical, and regular supply

of raw high-quality sand feed to the processing plant. In commercial mining terms, the quantities of sand mined each year at the

Lamesa Operation are considered modest. The sand deposit affords easy access with its shallow depth and large areal extent. As

such, mining plans for the Lamesa Mine are relatively simple and very flexible, able to be modified based on demand in a relatively

short time frame.

Geotechnically, the sand deposit is relatively competent and the mining depths so shallow such that slumping, or collapsing has not

been a detriment to the mining process. The pit design parameters discussed in Section 11.2.2 have been used with success at

similar proppant sand operations for decades.

Excessive inflow of groundwater into the pit is not expected. As such, dewatering before or during mining activities should be

manageable with drainage ditches and sumps. Flood waters from localized flash floods are a manageable risk. Onsite water ponds

can be used to hold any excessive ground or storm water.

13.4     Mining Sequence and Production

Mining of the sand deposit at the Lamesa Operation commenced in the third quarter of 2018 and have continued to the present day

without interruption. Over the past five years, the operation has mined almost 20 million tons of raw sand. During 2020, production

was reduced from approximately 4.8 million tons per year to 3.3 million tons in response to decreased customer demand due to the

COVID-19 pandemic. Production rebounded in 2021 and 2022 and is forecasted to rise in the LOM plan as illustrated in Figure

13.2, below.

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The proposed mining sequence is illustrated in Figure 13.3, on the following page. As shown, the proposed mining sequence

anticipates that the remaining northeastern quarter of the deposit will be mined out in a series of cuts from south to north (by 2027).

Production will then shift to the southern half of the Lamesa Pit and commence in a general north to south direction in 2028. At

which point, mining will shift to the western half of the deposit in 2029. Mining will be carried out in an east to west general direction

until depletion of the deposit in 2039. Any remaining reserves in the southern half of the deposit will be mined in 2032. Reclamation

will occur concurrently with production as depleted mining areas are returned to agreed-upon final design.

BOYD reviewed the LOM plans for U.S. Silica’s Lamesa Operation to determine whether the plans: (1) utilize generally accepted

engineering practices, and (2) align with historical and industry norms. Based on our assessment, it is BOYD’s opinion that the

forecasted production levels for the Lamesa Operation are reasonable, logical, and consistent with typical surface sand mining

practices in west Texas and historical results achieved by U.S. Silica.

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14.0    PROCESSING OPERATIONS

14.1    Overview

The Lamesa Operation’s processing facilities are located east of the active mining area on the same property as the mine.

Construction of the processing facilities and related infrastructure began in early 2018 and the first finished proppant sands were

produced in late 2018.

The production of finished proppant sand requires the processing of raw sand from the mine through two plants—the Wet

Processing Plant and the Dry Processing Plant. Figure 14.1, following this page, presents a simplified process flow from the mine to

the product distribution.

The processing facilities have a nominal capacity of 6.0 million tons of finished sand per year, based on operating 24 hours a day

and nearly 365 days per year.

BOYD is unaware of any reported interruptions, outages, shortages, or failures related to processing operations which have

materially affected the Lamesa Operation. Given the operation is well-established, we believe the risk of such events materially

affecting the estimates of silica sand reserves presented herein is low.

14.1.1    Wet Processing Plant
The Wet Processing Plant receives its raw sand feed from a ROM stockpile supplied by the mine. The raw sand is reclaimed by a
front-end loader and passed through a static grizzly to remove any organics and oversize material. After passing the grizzly screen,

the sand is washed to remove any material larger than ¼”. The remaining material is mixed with water to create a slurry that is
passed through a series of desliming cyclones and attrition scrubbers to remove clay and undersized (very fine) particles. The
deslimed material is then processed through a series of hydrosizers, hydro-cyclones, and vacuum filters to remove excess water.
The remaining WIP material is stockpiled outside on a drain pad to further reduce moisture before it is recovered and enters the Dry

Processing Plant.

The oversized and organics waste material produced by the Wet Processing Plant is stored in a dry waste stockpile for use in future
reclamation activities. The clay and very fine “slimes”, or tailings, are pumped to settling ponds where the water is recovered for

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future use. The water extracted by the hydrosizers, hydro-cyclones, vacuum filters, and drain pad is also recycled for use in the
processing operations.

14.1.2    Dry Processing Plant
A front-end loader is used to recover the WIP material from the drain pad and feed it into one of two dryer feed hoppers in the Dry
Processing Plant. The dryer feed hoppers feed sand through one of three rotary dryers. After drying, the sand is sized and sorted
using screens into 40/70-mesh, 40/140-mesh, and 100-mesh products. Any remaining oversize material at this point is screened off

and deposited in the dry waste stockpile. The final products are stored in truck loadout silos for eventual transfer to bulk trucks for
shipment to customers.

14.2 Production
The Lamesa Operation’s LOM plan forecasts increased production from the processing plant until the nominal production capacity is

reached. Recent annual production results and forecasted production over the expected life of the operation are provided in Figure
14.2.

14.3    Conclusion

Based on our review, it is BOYD’s opinion that the processing methods and existing equipment at the Lamesa Operation are
sufficient to achieve the forecasted production of finished proppant sand products.
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15.0    MINE INFRASTRUCTURE

15.1    Overview

All of the basic infrastructure required for the ongoing operations is in place at the Lamesa Operation. Figure 3.1 (page 3-2)

illustrates the general layout of the infrastructure at the Lamesa Operation.

The surface facilities currently located at the operation are well constructed and have the necessary capacity/capabilities to support

the Lamesa Operation’s near-term operating plans. Operational preference may lead to the upgrading of some existing facilities if

the operation expands in the future.

BOYD is unaware of any reported interruptions, outages, shortages, or failures related to infrastructure requirements which have

materially affected the Lamesa Operation. Given the operation is well-established, we believe the risk of such events materially

affecting the estimates of silica sand reserves presented herein is low.

15.2    Transportation

The Lamesa Operation is serviced by several roads maintained by the local municipality, county, and state governments. These

roads are either paved or well-maintained graded roadways. Road access is available year-round.

There is not any rail infrastructure available at the Lamesa Operation. All products are shipped via bulk trucks. The nearest railhead

is the Lubbock and Western in Brownfield, Texas, and the Plainsman Switching Company in Lubbock, Texas. Transloading is

required to use existing rail networks and U.S. Silica has no immediate plans to transport their products from the Lamesa Operation

using rail.

15.3    Utilities

Electric power for the processing plant is supplied by Lyntegar Electric Cooperative, Inc. (Lyntegar). A substation was built by

Lyntegar on the Lamesa site to distribute power to the facility. Power is transmitted by a series of above ground poles running

parallel to CR 9, then along CR C to the substation located east of the property. From the substation, power is distributed by a

series of overhead lines and buried power cords.

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Natural gas used by the processing plant is currently supplied by West Texas Gas Marketing, Inc. The gas is delivered by several

underground pipes running parallel to the CR 1064.

Water for industrial purposes is supplied by agreements to purchase with neighboring landowners and two onsite wells. Given the

semi-arid climate, recycling of industrial water is a priority. Potable water for consumption is delivered by truck in jugs and bottles.

There are no plans for connecting to a water utility network.

15.4 Tailings Disposal

The mining and processing of silica sand at the Lamesa Operation creates a substantial amount of waste tailings, a mixture of clay,

very fine sand, and other non-silica minerals. Tailings are typically disposed of in ponds (former mining pits) where the solid

materials settle to the bottom and water is decanted for reuse.

Existing tailings ponds are located directly to the west of the Lamesa Processing Plant. As mining progresses west, depleted pits

will become new tailing disposal sites. A freshwater pond is maintained on the property so water can be stored after reclaiming from

the tailings ponds.

15.5 Other Structures

Several other buildings are located on the property, including:

• Office buildings that house engineering, financial and administrative staff.
• Several support buildings used for machinery and maintenance activities.
• A warehouse for material storage and product bagging.
• Several product loadouts.
• Various pump structures and outbuildings.

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16.0    MARKET STUDIES

16.1    Market Overview

The Permian Basin’s proppant sand market is driven by unconventional horizontal drilling in the oil and gas industry. In the late

1990s, rapid advances in horizontal drilling and hydraulic fracturing (fracking) in North America ushered in large-scale commercial

oil and gas production. This fracking technique has been increasingly successful and modified over time to extract oil and gas held

in dense layers of shale rocks, whose low permeability had previously prevented the flow of hydrocarbons.

Hydraulic fracturing uses a mixture of water, chemicals, and proppant (natural sand or man-made sand-like substances) to fracture

shale rock and release hydrocarbons such as oil, natural gas and natural gas liquids. The proppant acts to keep the fractures open

(prop) while the pressurized fluids flow back up the well piping. Wells have become more productive with the addition of horizontal

drilling capabilities, longer lateral lengths, and multi-stage fracks.

To reduce costs, many Oilfield Services companies and E&P companies shifted from using only premium branded proppant sands,

which had higher delivered costs, to locally sourced and lower-priced “in-basin” proppant sands. The first in-basin proppant sand

deposits mined (late-2017) in the U.S. were located in the Permian Basin of Texas. Permian Basin E&P companies noted favorable

results from locally sourced proppant sands, and as such, nearly every other energy basin has experienced a period of exploration

to locate suitable local sources of proppant sands.

U.S. Silica operates in a highly competitive market that is characterized by a small number of large, national proppant sand

producers and a larger number of small, regional or local, privately-owned producers. Competition in the industry is based on: (1)

delivered price; (2) product consistency and quality; (3) supply capacity and reliability; and (4) customer service and technical

support. The Lamesa Operation’s substantial on-site product storage capacity and its strategic, in-basin location allows shipping

finished products to regional customers by truck. Since transportation costs are a significant portion of the total cost to customers of

proppant sands, development of the Lamesa, Texas plant as a regional frac sand facility in the Permian Basin allows U.S. Silica to

compete against proppant sand products being shipped from distant states like Wisconsin, Illinois, and Missouri.

16.2    Historical Sales

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U.S. Silica supplies a range of proppant sand products to major Oilfield Services

companies and E&P companies operating in the Permian Basin. The Lamesa Operation is the larger of two U.S. Silica proppant

sand operations in west Texas. Finished proppant sand products supplied by the Lamesa Operation primarily consist of non-API

standard 40/140-mesh and “100-mesh” (50/140-mesh) sized sand, with lesser amounts of API standard 40/70-mesh sized sand.

Recent historical sales data provided by U.S. Silica for the Lamesa Operation are summarized in Table 16.1, below.

Proppant sand demand dropped in 2020, as compared to 2019, due to the COVID-19 pandemic. However, recovery began in the

fourth quarter of 2020 and continued throughout 2021 and 2022. In 2020, the average selling price (ASP) for the Lamesa

Operation’s finished proppant sand products was $21.85 per sold ton. In 2021, the ASP dropped to $18.45 per sold ton; however,

the ASP rose to $31.39 per sold ton in 2022.

According to sales information provided by U.S. Silica for the Lamesa Operation:

• Contract sales account for approximately 60% of total product sales.

•

The top-five customer by sales revenue account for approximately 76% of total sales. U.S. Silica has a range of minimum
purchase supply agreements with customers with initial terms spanning through 2034.

BOYD is not aware of any material contracts for the sale of proppant sand from the Lamesa Operation.

16.3    Market Outlook

Despite rises in production, the Permian Basin’s demand for in-basin proppant sand outstripped supply in 2022. Consequently,

prices for in-basin finished proppant sand products rose significantly during the year. Sustained growth in demand for in-basin

proppant sand products is expected. Although it operates in a highly competitive market,

JOHN T. BOYD COMPANY

16-3

it is expected that the Lamesa Operation will experience increased demand for its products due, in part, to its low costs and

established customer base.

Having survived the challenging environment of 2019 and 2020, BOYD believes the Lamesa Operation should continue to prove

viable into the future notwithstanding a sustained and significant energy price collapse. Their low-cost mining and processing

operations, strategic in-basin location, and high-quality products help to create an advantage compared with other regional and

national proppant sand producers.

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JOHN T. BOYD COMPANY

17-1

17.0    PERMITTING AND COMPLIANCE

17.1    Permitting

Numerous permits are required by federal, state, and municipal law for mining, processing, and related activities at the Lamesa

Operation. U.S. Silica reports that necessary permits to support current and near-term operations are in place or pending approval.

New permits or permit revisions may be necessary from time to time to facilitate future operations. Given sufficient time and

planning, U.S. Silica should be able to secure new permits, as required, to maintain its planned operations within the context of

current regulations.

A description of the salient permitting requirements for the Lamesa Operation follows.

The Texas Commission on Environmental Quality (TCEQ) requires an Industrial Hazardous Waste (IHW) Solid Waste Registration

(#97503) which covers cleanup of hydraulic or lubricating oils from mobile equipment, general trash, and other hydrocarbon

contaminated materials.

A Phase I Environmental Site Assessment (ESA) was performed prior to construction of the Lamesa Operation. The assessment

included observations of oil and gas infrastructure including several gas and crude oil pipelines, one active oil well, several

abandoned and plugged oil and gas wells, historic oil and gas water ponds and several active and abandoned water wells.

Evidence of past crude oil leaks from pipelines adjacent to the property are also present. There were not any historical or

environmentally sensitive habitats found during the assessment.

U.S. Silica maintains a Stormwater Pollution Prevention Plan (SWPPP) at the Lamesa Operation to address requirements of the

federal Oil Pollution Prevention Regulations (40 CFR Part 122). The SWPPP outlines the treatment measures and best

management practices used on site to maintain stormwater discharges within the permit limitations. Stormwater that leaves the site

is authorized and outlined in the Stormwater Multi-Sector General Permit (MSGP) by the TCEQ (TXR05EB75).

A Petroleum Storage Tank (PST) registration (#89889) is held by the third-party contractor (O’Rourke Distribution Company) in

charge of mining operations for a double walled fuel tank used to fuel mobile equipment on site.

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17-2

Air emissions resulting from the processing plant and associated equipment at the Lamesa Operation are authorized by the TCEQ

Air Permit Program Permit #151650. Provisions of the permit specify the authorized maximum operating hours at the facility,

currently at 8,760 hours per year. The permit also allows for certain visible emissions at specific opacity. Quarterly visible emissions

and fugitive emissions determinations are required, as well as ambient air monitoring at the request of the TCEQ.

U.S. Silica maintains an annual Aggregate Production Operation registration with the TCEQ for annual production reporting.

Under current regulations, the State of Texas does not require reclamation or remediation of surface mined lands by aggregate

(including proppant sand) operations.

17.2    Compliance

U.S. Silica reports having an extensive environmental management and compliance process designed to follow or to exceed

industry standards.

In their 2021 corporate sustainability report, U.S. Silica reports:

•

Increasing the use of renewable energy sources.

• Enhancing water conservation and recycling efforts across our footprint, ensuring that drawing, using, and discharging fresh

water is done responsibly and in compliance with water management regulations and standards.

• Employing pollution prevention measures, such as increased operational efficiency and the reuse and recycling of materials, to

minimize the impact of our activities on the environment.

• Conducting annual evaluations of policies, procedures, and programs related to habitat conservation.

Mine safety is regulated by MSHA. They inspect the facilities a minimum of twice yearly. U.S. Silica’s safety record compares

favorably with its regional peers.

Based on our review of information provided by U.S. Silica and available public information, it is BOYD’s opinion that the Lamesa

Operation’s record of compliance with applicable mining, water quality, and environmental regulations is generally typical for that of

the industry. BOYD is not aware of any regulatory violation or compliance issue which would materially impact the proppant sand

reserve estimate.

17.3    Post-Mining Land Use and Reclamation

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17-3

There are no formal state or federal reclamation plans or permits required for the Lamesa Operation. However, general

requirements of U.S. Silica’s operating permits and licenses include:

• Stabilization of disturbed areas to prevent exposure of significant materials to stormwater which could discharge off-site.

• Demolition of water wells and septic tanks.

• Disposal of hazardous wastes.

Mine site reclamation costs are funded from U.S. Silica’s Asset Retirement Obligations (ARO) account. Funding of the ARO account

is included in the Lamesa Operation’s capital and operating costs discussed in Chapter 18 and included in the economic analysis

presented in Chapter 19. ARO cost estimates are reviewed annually. As a matter of good mining practice, U.S. Silica seeks to

conduct progressive reclamation throughout the operation’s mining life to minimize risk and costs at closure.

17.4    Community Engagement

BOYD is unaware of any plans, negotiations, agreements with local individuals or groups or commitments to ensure local

procurement and hiring.

U.S. Silica’s corporate sustainability report outlines the components of its core community engagement initiatives. It's stated

priorities include increasing charitable contributions to organization that support the local community and actively seeking

opportunities for volunteering and community engagement.

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18-1

18.0    CAPITAL AND OPERATING COSTS

18.1    Historical Financial Performance

Table 18.1 summarizes the past three years of financial data for the Lamesa Operation. We remind the reader that the COVID-19

pandemic caused severe economic, market, and other disruptions which began to affect U.S. Silica’s proppant sand operations in

the second quarter of 2020.

Gross revenues include income from product sales and shipping.

Total cash costs of sales include operating costs (i.e., mining, ongoing reclamation, processing, product loadout, and other related

costs) in addition to selling, general, and administrative expenses.

Capital expenditures include maintenance (sustaining) expenses and discretionary spending on continuous improvement projects to

drive and maintain cost efficiencies.

Based on the financial data presented above:

• Average realization increased from $21.85 per ton sold in 2020 to $31.39 per ton sold in 2022.

•

Total cash cost of sales also increased from $10.23 per ton sold in 2020 to $13.94 per ton sold in 2022.

• EBITDA margin increased marginally from 53.2% in 2020 to 55.6% in 2022.

• Capital expenditures totaled almost $4.2 million over the three years, averaging $0.37 per ton sold.

JOHN T. BOYD COMPANY

18-2

18.2    Estimated Costs

The production and unit cost estimates provided by U.S. Silica are based on actual past performance and their customary internal

budget review and approvals process. Operating volumes are well-defined and understood, as are mining and processing

productivities. As such, it is BOYD’s opinion that the production and financial projections are reasonable and are likely to be within ±

20% accuracy level.

This section contains forward-looking information related to capital and operating cost estimates for the Lamesa Operation.

There are inherent known and unknown risks and uncertainties associated with all mining operations. These risks, uncertainties,

and other factors are not quantifiable, but include, but are not limited to, adverse general economic conditions, operating hazards,

inherent uncertainties in interpreting engineering and geologic data, fluctuations in commodity prices and prices for operational

services, government regulation and political risks, as well as other risks commonly associated with the mining industry.

18.2.1    Projected Capital Expenditures

The Lamesa Operation and related facilities are fully developed and should not require any near-term major capital investment to

maintain full commercial production. Historically, the timing and amount of capital expenditures has been largely discretionary and

within U.S. Silica’s control. Their budgetary allocations for sustaining and discretionary capital expenditures over the next three

years is provided in Table 18.2, below.

BOYD considers the near-term detailed capital expenditure schedule as presented by U.S. Silica to be reasonable and
representative of the capital necessary to operate the Lamesa Operation.

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18-3

After 2025, capital expenditures are projected to increase 3% annually per year from 2025’s expenditures until the end of
operation’s life. As the Lamesa Operation is in a steady state of production, the projected capital expenditures are considered

reasonable and expected.

18.2.2    Projected Operating Costs
Operating cost estimates were developed based on recent actual costs and considering specific operational activity levels and cost
drivers. The estimates consider current and expected labor headcount and salaries, major consumables and unit prices, power
costs, and equipment and maintenance costs. The total operating cost estimate includes all site costs related to mining, processing,

and general and administrative activities.

In the near-term, U.S. Silica expects their unit operating costs to stay relatively consistent (on an uninflated basis). As such, the

projected total cash cost of sales over the life of the mine is $13.94 per ton sold. As the operation is in a steady state, BOYD

considers the future operating cost estimates to be reasonable and appropriate.

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JOHN T. BOYD COMPANY

19-1

19.0    ECONOMIC ANALYSIS

19.1    Approach

The economic analysis presented in this chapter was made for the purposes of confirming the commercial viability of the Lamesa

Operation’s reported proppant sand reserves and not for the purposes of valuing U.S. Silica, the Lamesa Operation, or its assets.

The economic analysis contains forward-looking information related to the projected operating and financial performance of the

Lamesa Operation and therefore involves inherent known and unknown risks and uncertainties, some of which may be outside of

U.S. Silica’s control. U.S. Silica, as with all mining companies, actively evaluates, changes, and modifies business and operating

plans in response to various factors that may affect operational and/or financial results. Actual results, production levels, operating

expenses, sales realizations, and all other modifying factors could vary significantly from the assumptions and estimates provided in

this analysis. Risk is subjective, as such, BOYD recommends that each reader should evaluate the project based on their own

investment criteria.

The financial model used for the purposes of the economic analysis has been prepared in-house by U.S. Silica as part of their

annual budgeting process. The model forecasts future free cash flow from proppant sand production and sales over the life cycle of

the Lamesa Operation using the annual forecasts of production, sales revenues, and operating and capital costs discussed earlier

in this report. A DCF analysis, in which future free cash flows are discounted to present value, is used to derive an NPV for the

proppant sand reserves. Use of DCF-NPV analysis is a standard method within the mining industry to assess the economic value of

a project after allowing for the cost of capital invested.

The financial evaluation of the Lamesa Operation has been undertaken on a simplified after-tax basis and does not reflect U.S.

Silica’s corporate tax structure. NPV is calculated using an after-tax discount rate of 12.5% (NPV ). Cash flows were assumed to

12.5

occur in the middle of each year and are discounted to mid-year 2022. Cost estimates and other inputs to the cash flow model for

the project have been prepared using constant 2022 money terms, i.e., without provision for inflation. Internal rate of return and

project payback were not calculated, as there was no initial investment (sunk costs) considered in the financial model provided

herein.

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19-2

A suite of sensitivities was calculated to evaluate the effect of the main drivers of economic performance, including variations in

sales prices, operating costs, and capital costs.

BOYD has reviewed the financial model and its inputs in detail. It is our opinion that the financial model provides a reasonable and

accurate reflection of the Lamesa Operation’s expected economic performance based on the assumptions and information available

at the time of our review.

19.2    Assumptions and Limitations

Cash flow projections for the Lamesa Operation have been generated from the annual forecasts of production, sales revenues, and

operating and capital costs discussed earlier in this report. A summary of the key assumptions and limitations is provided below:

• Sales volumes of finished proppant sand are expected to increase 2% per annum.

• ROM production requirements are based on an expected processing yield of 75% (the historic average) and are also projected

to increase 2% per annum. Forecasted ROM production is at or below the capacity of the existing mining equipment and related
infrastructure.

•

Forecasted revenues are based on sales of various grades of finished proppant sand with a weighted-average sales price of
$23.90 per ton.

• Capital and operating costs are discussed in Chapter 18. Capital expenditures are derived from budgetary allocations for the

first three years of the forecast and escalated thereafter at 3% per annum. Unit operating costs are expected to remain relatively
constant over the life of the operation at $13.94 per sold ton.

•

Taxes are based on combined Federal and State Tax rates totaling 26%

• Buildup of net working capital is equal to 25% of positive cash (operating) margins.

• Depreciation and amortization expenses are estimated as the average of the proceeding three years.

• Asset recovery/salvage values were not included in the valuation.

19.3    Financial Model Results

Estimated LOM pre-tax and after-tax cash flows for proppant sand production from the Lamesa Operation are presented in Table

19.1, on the following page.

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19-3

JOHN T. BOYD COMPANY

Table 19.2, below, provides a summary of the estimated remaining life of mine financial results for the Lamesa Operation.

19-4

DCF-NPV on a pre-tax and after-tax basis, using discount rates of 10%, 12.5% (the base case), and 15%, were calculated utilizing

the projected cash flows. Table 19.3 summarizes the results of the pre-tax and after-tax DCF-NPV analyses:

As shown, the pre-tax DCF-NPV ranges from approximately $309.6 million to $399.6 million. The after-tax DCF-NPV ranges from

approximately $262.2 million to $338.2 million.

The economic analysis confirms that the Lamesa Operation generates positive pre- and after-tax financial results and a real NPV

12.5

of $296.1 million. As such, it is BOYD’s

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19-5

opinion that the Lamesa Operation’s proppant sand reserves have demonstrated economic viability.

19.4    Sensitivity Analysis

Table 19.4, below, shows the sensitivity of the project after-tax for a cash flow discounted at 12.5% (NPV ) to a variation over a

12.5

range of 20% above and below the base case in: (1) average selling prices and (2) operating costs.

As might be expected, the project is most sensitive to changes in product pricing and operating costs. The project is less sensitive

to capital costs. There is little to no impact varying the capital costs from 70% to 130% of the base case.

This analysis demonstrates the project value to be relatively robust, with positive NPVs reported across the range of values

assessed.

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JOHN T. BOYD COMPANY

20-1

20.0    ADJACENT PROPERTIES

Exploration data, including the results of drilling and sampling campaigns conducted by U.S. Silica, have been collected from

properties located adjacent to the Lamesa Operation (refer to Figure 7.1 on page 7-5) and used in the estimation of proppant sand

resources and reserves as reported herein.

A competitor proppant sand producer recently began mining operations on the property located immediately north of the Lamesa

Operation. BOYD is unaware of any other mining or exploration activities having occurred on adjacent properties.

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21-1

21.0    OTHER RELEVANT DATA AND INFORMATION

BOYD is not aware of any additional information which would materially impact the proppant sand resource and reserve estimates

reported herein.

JOHN T. BOYD COMPANY

22-1

22.0    INTERPRETATION AND CONCLUSIONS

22.1    Audit Findings

BOYD’s independent technical assessment was conducted in accordance with S-K 1300 and concludes:

• Sufficient data have been obtained through site exploration and sampling programs and mining operations to support the

geological interpretations of the sand deposit within the controlled property of the Lamesa Operation. The data are of sufficient
quantity and reliability to reasonably support the proppant sand resource and reserve estimates presented in this report.

• BOYD is of the opinion that our data verification efforts: (1) adequately confirm the reasonableness of the geologic

interpretations, resource estimation criteria, and economic assumptions; and (2) support the use of the data in proppant sand
resource/reserve estimation.

•

•

•

The 79.6 million saleable product tons of proppant sand reserves (as of December 31, 2022) identified on the property are
reasonably and appropriately supported by technical studies, which consider expected geologic conditions, planned mining and
processing operations, forecasted product revenues, and operating and capital cost estimates. As such, BOYD is of the opinion
that there are reasonable expectations that the stated proppant sand reserves for the Lamesa Operation are technically,
economically, and legally extractable as of December 31, 2022.

In addition to the reported reserves, U.S. Silica controls approximately 5.4 million in-place tons of measured and indicated
proppant sand resources and 5.0 million in-place tons of inferred proppant sand resources at the Lamesa Operation. It is
BOYD’s opinion that the stated proppant sand resources have been reported using economic and mining assumptions to
support the reasonable potential for eventual economic extraction.

There is no other relevant information material to the Lamesa Operation that is necessary to make this technical report summary
not misleading.

22.2    Significant Risks and Uncertainties

As a mining operation with an established operating history, the purpose of U.S. Silica’s periodic mine planning exercises is to: (1)

collect and analyze sufficient data to reduce or to eliminate risk in the technical components of the project, and (2) to refine

economic projections based on current data. There is a high degree of certainty for this project under the current and foreseeable

operating environment. A general assessment of risk is presented in the relevant sections of this report.

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JOHN T. BOYD COMPANY

23-1

23.0    RECOMMENDATIONS

Based on the scope of our assignment, BOYD has no recommendations regarding the Lamesa Operation. It is our understanding

that U.S. Silica continuously reviews and improves operating practices as a matter of course.

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24-1

A list of supporting information is provided in Section 2.4. Additional references are cited as footnotes in the report as required.

24.0    REFERENCES

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25-1

25.0    RELIANCE ON INFORMATION PROVIDED BY REGISTRANT

In the preparation of this report, BOYD has relied, exclusively and without independent verification, upon information furnished by

U.S. Silica as presented in Table 25.1, below.

BOYD exercised due care in reviewing the information provided by U.S. Silica within the scope of our expertise and experience

(which is in technical and financial mining issues) and concluded the data are reasonable and appropriate considering the status of

the subject properties and the purpose for which this report was prepared. We have no reason to believe that any material facts

have been withheld or misstated, or that further analysis may reveal additional material information. However, the accuracy of the

results and conclusions of this report are reliant on the accuracy of the information provided by U.S. Silica.

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JOHN T. BOYD COMPANY

TECHNICAL REPORT SUMMARY

PROPPANT SAND RESOURCES AND RESERVES

CRANE OPERATION

Crane County, Texas

Prepared For

U.S. SILICA COMPANY

Katy, Texas

By

John T. Boyd Company

Mining and Geological Consultants

Pittsburgh, Pennsylvania

Report No. 3076.020

FEBRUARY 2023

 John T. Boyd Company

    Mining and Geological Consultants

File: 3076.020

February 22, 2023

 John T. Boyd Company

    Mining and Geological Consultants

U.S. Silica Company
24275 Katy Freeway, Suite 600
Katy, TX 77494-7271

Attention:    Mr. Terry Lackey

    Mining Director

Subject:    Technical Report Summary
        Proppant Sand Resources and Reserves
        Crane Operation
        Crane County, Texas

Ladies and Gentlemen:

The John T. Boyd Company (BOYD) was retained by U.S. Silica Company (U.S. Silica) to complete an independent technical
assessment of the proppant sand resource and reserve estimates for the Crane Operation as of December 31, 2022.

This technical report summary: (1) summarizes material technical and geoscientific information for the subject mining property, (2)
provides the conclusions of our technical assessment, and (3) provides a statement of proppant sand resources and reserves for
the Crane Operation.

Respectfully submitted,

JOHN T. BOYD COMPANY
By:

John T. Boyd II
President and CEO

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    TABLE OF CONTENTS

    Page
LETTER OF TRANSMITTAL

TABLE OF CONTENTS

GLOSSARY AND ABBREVIATIONS

1.0    EXECUTIVE SUMMARY     1-1
    1.1    Introduction     1-1
    1.2    Property Description     1-1
    1.3    Geology     1-3
    1.4    Exploration     1-3
    1.5    Proppant Sand Resources and Reserves     1-3
    1.6    Operations     1-5
        1.6.1    Mining     1-5
        1.6.2    Processing     1-5
        1.6.3    Other Infrastructure     1-6
    1.7    Financial Analysis     1-6
        1.7.1    Market Analysis     1-6
        1.7.2    Capital and Operating Cost Estimates     1-7
        1.7.3    Economic Analysis     1-8
    1.8    Permitting Requirements     1-9
    1.9    Conclusions     1-10

2.0    INTRODUCTION     2-1
    2.1    Registrant     2-1
    2.2    Terms of Reference and Purpose     2-1
    2.3    Expert Qualifications     2-2
    2.4    Principal Sources of Information     2-3
    2.5    Personal Inspections     2-3
    2.6    Report Version     2-4
    2.7    Units of Measure     2-4

3.0    PROPERTY DESCRIPTION     3-1
    3.1    Location     3-1
    3.2    Property Rights    3-1
    3.3    Encumbrances    3-3
        3.3.1 Fees and Royalties    3-3
        3.3.2 Permitting Requirements    3-3
        3.3.3 Mining Restrictions    3-3
        3.3.4 Other Significant Factors or Risks    3-4

4.0    PHYSIOGRAPHY, ACCESSIBILITY, AND INFRASTRUCTURE     4-1
    4.1    Topography, Elevation, and Vegetation     4-1
    4.2    Accessibility     4-1
    4.3    Climate    4-1
    4.4    Infrastructure Availability and Sources     4-2

JOHN T. BOYD COMPANY

        
    
    TABLE OF CONTENTS    - Continued  

    Page

5.0    HISTORY     5-1
    5.1    Reserve Acquisition     5-1
    5.2    Mine Development     5-1

6.0    GEOLOGICAL SETTING, MINERALIZATION, AND DEPOSIT     6-1
    6.1    Regional Geology     6-1
    6.2    Local Geology     6-1
        6.2.1    General Stratigraphy     6-1
        6.2.2    Structural Geology     6-3
    6.3    Property Geology     6-3

7.0    EXPLORATION DATA     7-1
    7.1    Background     7-1
    7.2    Exploration Procedures     7-1
        7.2.1    Drilling     7-1
        7.2.2    Sampling Procedures     7-2
        7.2.3    Sand Testing     7-2
        7.2.4    Other Exploration Methods     7-3
    7.3    Exploration Results     7-4
        7.3.1    Summary of Exploration     7-4
        7.3.2    Sand Quality    7-6
        7.3.3    Grain Size Distribution    7-6
    7.4    Data Verification     7-8
    7.5    Adequacy of Exploration and Sampling    7-8

8.0    SAMPLE PREPARATION, ANALYSIS, AND SECURITY     8-1

9.0    DATA VERIFICATION     9-1

10.0    MINERAL PROCESSING AND METALLURGICAL TESTING     10-1

11.0    PROPPANT SAND RESOURCE ESTIMATE     11-1
    11.1    Applicable Standards and Definitions     11-1
    11.2    Proppant Sand Resources     11-2
        11.2.1     Methodology     11-2
        11.2.2     Estimation Criteria     11-2
        11.2.3     Classification     11-3
        11.2.4     Proppant Sand Resource Estimate     11-5
        11.2.5     Validation     11-5

12.0    PROPPANT SAND RESERVE ESTIMATE     12-1
    12.1    Applicable Standards and Definitions     12-1
    12.2    Proppant Sand Reserves     12-2
        12.2.1     Methodology    12-2
        12.2.2     Classification    12-3
        12.2.3     Proppant Sand Reserve Estimate     12-5
        12.2.4     Reconciliation with Previous Estimates     12-6

JOHN T. BOYD COMPANY

    
    
    
    TABLE OF CONTENTS    - Continued  

    Page

13.0    MINING METHODS     13-1
    13.1    Mining Operations    13-1
    13.2    Mine Equipment and Staffing     13-2
        13.2.1     Mine Equipment     13-2
        13.2.2     Staffing     13-3
    13.3    Engineering and Planning     13-3
    13.4    Mining Sequence and Production     13-3

14.0    PROCESSING OPERATIONS     14-1
    14.1    Overview     14-1
        14.1.1 Wet Processing Plant    14-1
        14.1.2 Dry Processing Plant    14-2
    14.2    Production     14-4
    14.3    Conclusion     14-4

15.0    MINE INFRASTRUCTURE     15-1
    15.1    Overview     15-1
    15.2    Transportation     15-1
    15.3    Utilities    15-1
    15.4    Tailings Disposal    15-2
    15.5    Other Structures    15-2

16.0    MARKET STUDIES     16-1
    16.1    Market Overview     16-1
    16.2    Historical Sales     16-2
    16.3    Market Outlook     16-2

17.0    PERMITTING AND COMPLIANCE     17-1
    17.1    Permitting     17-1
    17.2    Compliance     17-2
    17.3    Post-Mining Land Use and Reclamation    17-3
    17.4    Community Engagement    17-3

18.0    CAPITAL AND OPERATING COSTS     18-1
    18.1    Historical Financial Performance     18-1
    18.2    Estimated Costs     18-2
        18.2.1 Projected Capital Expenditures     18-2
        18.2.2 Projected Operating Costs    18-3

19.0    ECONOMIC ANALYSIS     19-1
    19.1    Approach     19-1
    19.2    Assumptions and Limitations     19-2
    19.3    Financial Model Results    19-2
    19.4    Sensitivity Analysis    19-5

20.0    ADJACENT PROPERTIES     20-1

JOHN T. BOYD COMPANY

    
    TABLE OF CONTENTS    - Continued  

    Page

21.0    OTHER RELEVANT DATA AND INFORMATION     21-1

22.0    INTERPRETATION AND CONCLUSIONS     22-1
    22.1    Audit Findings     22-1
    22.2    Significant Risks and Uncertainties     22-1

23.0    RECOMMENDATIONS     23-1

24.0    REFERENCES     24-1

25.0    RELIANCE ON INFORMATION PROVIDED BY REGISTRANT     25-1

JOHN T. BOYD COMPANY

    TABLE OF CONTENTS    - Continued  

    Page

List of Tables
1.1    Crane Operation Proppant Sand Resources (as of December 31, 2022)    1-4
1.2    Crane Operation Proppant Sand Reserves (as of December 31, 2022)     1-4
1.3    Financial Results    1-8
1.4    DCF-NPV Analysis    1-9
7.1    Weighted Average Particle Size Distribution    7-6
7.2    Crane Operation Proppant Sand Characteristics     7-7
11.1    Proppant Sand Resource Classification Criteria    11-4
11.2    Crane Operation Proppant Sand Resources (as of December 31, 2022)    11-5
12.1    Crane Operation Proppant Sand Reserves (as of December 31, 2022)    12-5
13.1    Employees by Classification    13-3
16.1    Historical Sales Data     16-2
18.1    Historical Financials    18-1
18.2    Projected Capital Costs    18-2
19.1    Annual Production and Cash Flow Forecast Crane Operation     19-3
19.2    Financial Results    19-4
19.3    DCF-NPV Analysis     19-4
19.4    After-Tax NPV  Sensitivity Analysis ($ millions)     19-5
25.1    Information Relied Upon from Registrant    25-1

12.5

JOHN T. BOYD COMPANY

    TABLE OF CONTENTS    - Continued  

    Page

List of Figures
1.1    General Location Map     1-2
3.1    Map Showing Site Layout Crane Operation     3-2
6.1    Generalized Stratigraphic Chart, Surficial Deposits of Crane, Texas    6-2
6.2    Map Showing Proppant Sand Thickness Isopaches Crane Operation    6-5
6.3    Cross-Section A – A’ Crane Operation    6-6
7.1    Map Showing Drill Hole Locations Crane Operation    7-5
12.1    Relationship Between Mineral Resources and Mineral Reserves    12-2
12.2    Map Showing Mineral Reserve Classification Crane Operation    12-4
13.1    Active Quarry Face at the Crane Operation    13-2
13.2    Recent Historical and LOM Forecasted Mining Production    13-4
13.3    Map Showing Life-of-Mine Plan Crane Operation    13-5
14.1    Simplified Flow Sheet Crane Operation    14-3
14.2    Recent Historical and LOM Forecasted Processing Plant Production    14-4

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1

000

$

%

AEI

AMSL

API

ARO

ASP

ASTM

BNSF

BOYD

CapEx

Constant Dollar

CSX

DCF

Discount Rate

E&P

EBIT

EBITDA

ESA

Frac Sand

:

:

:

:

:

:

:

:

:

:

:

:

:

:

:

:

:

:

:

:

:

GLOSSARY OF ABBREVIATIONS AND DEFINITIONS

Thousand(s)

US dollar(s)

Percent or percentage

Associated Environmental Industries, Corp.

Above mean sea level

American Petroleum Institute

Asset Retirement Obligation(s)

Average Selling Price

ASTM International (formerly American Society for Testing and Materials)

BNSF Railway Company

John T. Boyd Company

Capital expenditures

A monetary measure that is not influenced by inflation and used to compare time periods.
Sometimes referred to as “real dollars”.

CSX Transportation

Discounted Cash Flow

A rate of return used to discount future cash flows based on the return investors expect to receive
from their investment.

Exploration and Production

Earnings before interest and taxes

Earnings before interest, taxes, depreciation, and amortization

Environmental Site Assessment

See “Proppant Sand”

JOHN T. BOYD COMPANY

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    GLOSSARY OF ABBREVIATIONS AND DEFINITIONS - Continued 

ft

Indicated Proppant Sand
Resource

Inferred Proppant Sand
Resource

IRR

ISO

ISP

lb

LOM

Lyntegar

:

:

:

:

:

:

:

:

Foot/feet

That part of a proppant sand resource for which quantity and quality are estimated based on
adequate geological evidence and sampling. The level of geological certainty associated with an
indicated proppant sand resource is sufficient to allow a qualified person to apply modifying
factors in sufficient detail to support mine planning and evaluation of the economic viability of the
deposit. Because an indicated proppant sand resource has a lower level of confidence than the
level of confidence of a measured proppant sand resource, an indicated proppant sand resource
may only be converted to a probable proppant sand reserve.

That part of a proppant sand resource for which quantity and quality are estimated based on
limited geological evidence and sampling. The level of geological uncertainty associated with an
inferred proppant sand resource is too high to apply relevant technical and economic factors likely
to influence the prospects of economic extraction in a manner useful for evaluation of economic
viability. Because an inferred proppant sand resource has the lowest level of geological
confidence of all proppant sand resources, which prevents the application of the modifying factors
in a manner useful for evaluation of economic viability, an inferred proppant sand resource may
not be considered when assessing the economic viability of a mining project, and may not be
converted to a proppant sand reserve.

Internal rate-of-return

International Organization for Standardization

Industrial and Specialty Products

Pound

Life-of-Mine

Lyntegar Electric Cooperative, Inc.

JOHN T. BOYD COMPANY

    
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    GLOSSARY OF ABBREVIATIONS AND DEFINITIONS - Continued 

Measured Proppant Sand
Resource

Mesh

Mineral Reserve

Mineral Resource

Modifying Factors

MSHA

MSGP

NTU
NPV

O&G

:

:

:

:

:

:

:
:

:

That part of a proppant sand resource for which quantity and quality are estimated based on
conclusive geological evidence and sampling. The level of geological certainty associated with a
measured proppant sand resource is sufficient to allow a qualified person to apply modifying
factors, as defined herein, in sufficient detail to support detailed mine planning and final
evaluation of the economic viability of the deposit. Because a measured proppant sand resource
has a higher level of confidence than the level of confidence of either an indicated proppant sand
resource or an inferred proppant sand resource, a measured proppant sand resource may be
converted to a proven proppant sand reserve or to a probable proppant sand reserve

A measurement of particle size often used in determining the size distribution of granular material.

See “Proppant Sand Reserve”

See “Proppant Sand Resource”

The factors that a qualified person must apply to indicated and measured proppant sand
resources and then evaluate to establish the economic viability of proppant sand reserves. A
qualified person must apply and evaluate modifying factors to convert measured and indicated
proppant sand resources to proven and probable proppant sand reserves. These factors include
but are not restricted to: mining; processing; infrastructure; economic; marketing; legal;
environmental compliance; plans, negotiations, or agreements with local individuals or groups;
and governmental factors. The number, type and specific characteristics of the modifying factors
applied will necessarily be a function of and depend upon the mineral, mine, property, or project.

Mine Safety and Health Administration. A division of the U.S. Department of Labor

Multi-Sector General Permit

Nephelometric turbidity units.
Net Present Value

Oil and Gas

JOHN T. BOYD COMPANY

    
    4

    GLOSSARY OF ABBREVIATIONS AND DEFINITIONS - Continued 

Probable Proppant Sand
Reserve

Production Stage Property

Proppant Sand

Proppant Sand Reserve

Proppant Sand Resource

Proven Proppant Sand
Reserve

PSI

PST

QP

:

:

:

:

:

:

:

:

:

The economically mineable part of an indicated and, in some cases, a measured proppant sand
resource.

A property with material extraction of proppant sand reserves.

Proppant (frac) sand is a naturally occurring, high silica content quartz sand, with grains that are
generally well rounded and exhibit high compressive strength characteristics relative to other
proppant sand. It is utilized as a prop or “proppant” in unconventional shale frac well completions.

Proppant sand reserve is an estimate of tonnage and grade or quality of indicated and measured
proppant sand resources that, in the opinion of the qualified person, can be the basis of an
economically viable project. More specifically, it is the economically mineable part of a measured
or indicated Proppant sand resource, which includes diluting materials and allowances for losses
that may occur when the material is mined or extracted.

Proppant sand resource is a concentration or occurrence of material of economic interest in or on
the Earth's crust in such form, grade or quality, and quantity that there are reasonable prospects
for economic extraction. A proppant sand resource is a reasonable estimate of mineralization,
taking into account relevant factors such as cut-off grade, likely mining dimensions, location or
continuity, that, with the assumed and justifiable technical and economic conditions, is likely to, in
whole or in part, become economically extractable. It is not merely an inventory of all
mineralization drilled or sampled.

The economically mineable part of a measured proppant sand resource which can only result
from conversion of a measured proppant sand resource.

Pounds per square inch

Petroleum Storage Tank

Qualified Person

JOHN T. BOYD COMPANY

    
    5

    GLOSSARY OF ABBREVIATIONS AND DEFINITIONS - Continued 

Qualified Person

:

An individual who is:

1. A mineral industry professional with at least five years of relevant experience in the type of

mineralization and type of deposit under consideration and in the specific type of activity that
person is undertaking on behalf of the registrant; and

2. An eligible member or licensee in good standing of a recognized professional organization at
the time the technical report is prepared. For an organization to be a recognized professional
organization, it must:

a. Be either:

i. An organization recognized within the mining industry as a reputable professional

association; or

ii.A board authorized by U.S. federal, state, or foreign statute to regulate professionals

in the mining, geoscience, or related field;

b. Admit eligible members primarily based on their academic qualifications and experience;
c. Establish and require compliance with professional standards of competence and ethics;
d. Require or encourage continuing professional development;
e. Have and apply disciplinary powers, including the power to suspend or expel a member

regardless of where the member practices or resides; and

f. Provide a public list of members in good standing.

Run-of-Mine. The processing feed material, including proppant sand and any inseparable waste,
excavated from the mine.

U.S. Securities and Exchange Commission

Subpart 1300 and Item 601(b)(96) of the U.S. Securities and Exchange Commission’s Regulation
S-K

Stormwater Pollution Prevention Plan

Short Ton. A unit of weight equal to 2,000 pounds

Texas Commission on Environmental Quality

U.S. Silica Company, its parent company (U.S. Silica Holdings, Inc.) and its consolidated
subsidiaries as a combined entity.

:

:

:

:

:

:

:

ROM

SEC

S-K 1300

SWPPP

Ton

TCEQ

U.S. Silica

WIP

: Work-in-progress

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JOHN T. BOYD COMPANY

    
 
 
1-1

1.0    EXECUTIVE SUMMARY

1.1    Introduction

U.S. Silica’s Crane Operation is an active surface proppant sand mining and processing operation that has been producing finished

proppant (frac) sand products since 2018.

BOYD prepared this technical report summary for U.S. Silica in support of their disclosure of proppant sand reserves for the Crane

Operation in accordance with Subpart 1300 and Item 601(b)(96) of the SEC's Regulation S-K (S-K 1300). The purpose of this report

is threefold: (1) to summarize material technical and geoscientific information for the subject mining property, (2) to provide the

conclusions of our technical assessment, and (3) to provide a statement of proppant sand resources and/or reserves for the Crane

Operation.

Information used in our assessment was obtained from: (1) files provided by U.S. Silica, (2) discussions with U.S. Silica personnel,

(3) records on file with regulatory agencies, (4) public sources, and (5) nonconfidential information in BOYD’s possession.

Unless otherwise noted, the effective date of the information, including estimates of proppant sand reserves, is December 31, 2022.

Weights and measurements are expressed in the US customary measurement system throughout this report.

1.2    Property Description
U.S. Silica’s Crane Operation is a surface proppant sand mining and processing operation located 25 miles west of the City of

Odessa in Crane County, Texas. The cities of Lubbock and Dallas, Texas, are located approximately 147 miles northeast and 355
miles east, respectively, of the Crane Operation. The general location of the Crane Operation is provided in Figure 1.1, following this
page.

The property comprises ±3,200 generally contiguous acres of surface and mineral rights wholly owned by U.S. Silica. A royalty of $1
per ton of finished sand sold is payable to the former owners of the property. The mine offices, maintenance facilities, processing
plant, loadout facilities, and tailings ponds are located on the northeast corner of the property while the active and future mining
areas are located to the south and west.

JOHN T. BOYD COMPANY

1-2

1-3

1.3    Geology
The Crane Operation’s target sand bearing formation is the unconsolidated sand dunes of the Llano Estacado, which is a series of

dune fields of varying extent and thickness. Locally these sand dunes are known as the “Monahan’s Sandhills.”

At the Crane Operation, the Monahan Sandhills are a series of gently rolling sand dunes overlying a sandstone unit. The formation
is a white to buff, fine- to medium-grained ortho-quartzite. It contains rounded, clear polished sand quartz grains with minor
secondary silica and clay cement. The sandstone unit is in turn underlain by a predominantly limestone unit. Where covered, the

sand is overlain by a negligible layer of overburden material consisting of vegetation and oversize rock. The two sand units are
generally mineable from the ground surface down to the basal limestone unit. Combined thickness of both sand units ranges from
10 to 80 ft across the property.

1.4    Exploration

U.S. Silica has conducted two exploration campaigns on the Crane property. The 26 drill holes completed in and around the
property were utilized to define the lateral extent, thickness, particle size distribution, and mineralogy of the target sand deposit at
the Crane Operation.

BOYD’s audit indicates that in general: (1) U.S. Silica has performed extensive drilling and sampling work on the subject property,

(2) the work completed has been done by competent personnel, and (3) the amount of data available combined with extensive
knowledge and recent production of the sand deposit, are sufficient to confirm the thickness, lateral extents, and quality
characteristics of the Crane proppant sand reserves.

1.5    Proppant Sand Resources and Reserves
As shown in Table 1.1, following this page, U.S. Silica owns approximately 2.2 million in place tons of indicated proppant sand
resources and 16.4 million in place tons of

JOHN T. BOYD COMPANY

inferred proppant sand resources, exclusive of proppant sand reserves, at the Crane Operation, as of December 31, 2022.

1-4

While these “additional” proppant sand resources have not been included in the Crane Operation’s life-of-mine (LOM) plan, they are
considered to have prospects for eventual economic extraction by virtue of their similarity—in terms of demonstrated extraction
methods and expected finished product qualities—to those converted to proppant sand reserves.

U.S. Silica’s estimated surface mineable proppant sand reserves for the Crane Operation total 121.9 million saleable product tons
remaining as of December 31, 2022. The proppant sand reserves are fully owned by U.S. Silica and are summarized in Table 1.2,
below.

The Crane Operation has a well-established practice of mining, processing, and selling proppant sand products into Oil and Gas

market. BOYD has concluded that sufficient studies have been undertaken to enable the proppant sand resources to be converted

to

JOHN T. BOYD COMPANY

1-5

proppant sand reserves based on proposed operating methods and forecasted costs and revenues.

1.6    Operations

1.6.1    Mining

Contractors are employed to conduct surface mining on the Crane property. The target sand deposit is excavated using

conventional truck and excavator methods. Generally, the negligibly thin layer of overburden is mined with the unconsolidated sand

dunes; however, small areas of caliche overburden are present and must be removed prior to mining the sand. The sand does not

require drilling or blasting. Excavators and/or front-end loaders are used to load articulated haul trucks with disaggregated sand.

The haul trucks deliver raw sand material to run-of-mine (ROM) stockpile located near the processing facilities.

Over the past three years, the operation has mined almost 7.8 million tons of raw sand. During mid-2020, production was halted due

to the COVID-19 pandemic. Production resumed in April of the following year. U.S. Silica’s LOM plan forecasts mining 147.8 million

tons of ROM proppant sand at a rate of 4.2 million tons in 2023 increasing to 4.8 million in 2030 and continuing until the forecasted

end of life for the operation in 2053.

1.6.2    Processing

The Crane Operation’s Wet and Dry Processing Plants are located in the northeastern corner of the property.

Mined ROM material from the pit arrives at the Wet Processing Plant by truck, where it is screened and washed to remove

vegetation, oversize (> 40-mesh) and fine waste (<200-mesh) material. The remaining material is mixed with water to create a slurry

that is passed through a series of desliming cyclones and attrition scrubbers to remove clay and undersized (very fine) particles.

The deslimed material is then processed through a series of hydrosizers, hydro-cyclones, and vacuum filters to remove excess

water. The remaining “work-in-progress” (WIP) material is stockpiled outside on a drain pad to further reduce moisture before it is

recovered and enters the Dry Processing Plant. Within the Dry Processing Plant, the WIP sand is dried, sized and sorted. The

40/70-mesh and 100-mesh dry finished products are stored in silos prior to loading in bulk truck for shipment to customers in the

Permian Basin.

The processing operations have a nominal capacity of 4 million tons of finished sand per year. Based on our review, it is BOYD’s

opinion that the processing methods and

JOHN T. BOYD COMPANY

1-6

existing equipment at the plant will be sufficient for the forecasted production levels over the life of the operation.

1.6.3    Other Infrastructure

The Crane Operation is supported by various utilities and transportation networks needed to allow processing and transportation of

finished proppant sands.

Electricity to the Crane site is delivered through an above-ground network that terminates at a substation at the processing facility,

and from there electricity is distributed via several underground and above-ground powerlines.

Initial makeup water for industrial use is obtained through a regional water gathering and transport system for mining and oil and

gas operators in west Texas. Potable water is delivered by truck in jugs and bottles.

Natural gas is supplied via several underground pipelines.

Tailings from processing consist generally of clays, silts, and very fine sands, which are typically disposed of in old mining pit

impoundments. The tailings ponds are currently located north of the processing plant and are designed to accommodate rejects

produced during the next several years of production. At that time, it is expected that mining will have advanced to the westward,

and the mined pits will be used for tailings.

Transportation needs are met through a well-developed road network on both paved and graded dirt roads. No local railheads are

present.

1.7    Financial Analysis

1.7.1    Market Analysis

U.S. Silica supplies a range of proppant sand products to major Oilfield Services

companies and Exploration and Production (E&P) companies operating in the Permian Basin. The Crane Operation is one of U.S.

Silica’s two proppant sand operations in west Texas. Finished proppant sand products supplied by the Crane Operation primarily

consist of non-API standard 40/140-mesh and “100-mesh” (50/140-mesh) sized sand, with lesser amounts of API standard 40/70-

mesh sized sand.

U.S. Silica operates in a highly competitive market that is characterized by a small number of large, national proppant sand

producers and a larger number of small, regional or local, privately-owned producers. Competition in the industry is based on: (1)

JOHN T. BOYD COMPANY

1-7

delivered price; (2) product consistency and quality; (3) supply capacity and reliability; and (4) customer service and technical

support. The Crane Operation’s substantial on-site product storage capacity and its strategic, in-basin location allows shipping

finished products to reginal customers by truck. Since transportation costs are a significant portion of the total cost to customers of

proppant sands, development of the Crane, Texas plant as a regional sand facility in the Permian Basin allows U.S. Silica to

compete against products being shipped from regional producers as well as distant states like Wisconsin, Illinois, and Missouri.

U.S. Silica’s product sales were materially impacted by the COVID-19 pandemic, with production suspending in mid-2020. However,

their sales volumes and revenues have recovered substantially, and continued growth is expected over the long-term.

1.7.2    Capital and Operating Cost Estimates

The Crane Operation’s financial performance over the last years is summarized as follows:

• Average realization increased from $22.06 per ton sold in 2020 to $30.78 per ton sold in 2022.

•

Total cash cost of sales decreased from $16.67 per ton sold in 2020 to $14.15 per ton sold in 2022.

• EBITDA margin increased marginally from 24.4% in 2020 to 54.0% in 2022.

• Capital expenditures totaled almost $3.8 million over the three years, averaging $0.54 per ton sold.

Forward-looking production and unit cost estimates are based on actual past performance and subject to U.S. Silica’s customary

internal budget review and approvals process. In BOYD’s opinion, operating volumes are well-defined and understood, as are

mining and processing productivities.

The Crane Operation and related facilities are fully developed and should require no near-term major capital investment to maintain

full commercial production. Historically, the timing and amount of capital expenditures has been largely discretionary and within U.S.

Silica’s control. Their budgetary allocations for sustaining and discretionary capital expenditures over the next three years totals

$2.2 million. Thereafter, capital expenditures are expected to rise yearly at a rate of 3% annually starting in 2024. BOYD considers

the near-term detailed capital expenditure schedule as presented by U.S. Silica to be reasonable and representative of the capital

necessary to operate the Crane Operation.

JOHN T. BOYD COMPANY

1-8

Operating cost estimates were developed based on recent actual costs and considering specific operational activity levels and cost

drivers. In the near-term, U.S. Silica expects their unit operating costs to stay relatively level (on an uninflated basis). As such, the

projected total cash cost of sales over the life of the mine is $14.15 per ton sold. As the operation is in a steady state, BOYD

considers the future operating cost estimates to be reasonable and appropriate.

1.7.3    Economic Analysis

An economic analysis of the Crane Operation was prepared in-house by U.S. Silica as part of their annual budgeting process. The

financial model forecasts future free cash flow from proppant sand production and sales over the life cycle of the Crane Operation

using the annual forecasts of production, sales revenues, and operating and capital costs.

Table 1.3, below, provides a summary of the estimated financial results for the remaining life of the Crane Operation.

JOHN T. BOYD COMPANY

Table 1.4 summarizes the results of the pre-tax and after-tax discounted cash flows (DCF) and net present value (NPV) analyses for

the Crane Operation.

1-9

The NPV estimate was made for purposes of confirming the economic viability of the reported proppant sand reserves and not for

purposes of valuing the U.S. Silica, Crane Operation, or its assets. Internal rate-of-return (IRR) and project payback were not

calculated, as there was no initial investment considered in the financial analysis presented herein.

BOYD reviewed the financial model and its inputs in detail, and opined that model provides a reasonable and accurate reflection of

the Crane Operation’s expected economic performance based on the assumptions and information available at the time of our

review.

1.8    Permitting Requirements

Numerous permits are required by federal and state law for mining, processing, and related activities at the Crane Operation, which

U.S. Silica reports are in place or pending approval. New permits or permit revisions may be necessary from time to time to facilitate

future operations. Given sufficient time and planning, U.S. Silica should be able to secure new permits, as required, to maintain its

planned operations within the context of current regulations.

U.S. Silica reports having an extensive environmental management and compliance process designed to follow or to exceed

industry standards.

Mine safety is regulated by the U.S. Department of Labor’s Mine Safety and Health Administration (MSHA). MSHA inspects the

facilities a minimum of twice yearly. U.S. Silica’s safety record compares favorably with its regional peers.

BOYD is not aware of any regulatory violation or compliance issue which would materially impact the proppant sand reserve

estimate.

JOHN T. BOYD COMPANY

1-10

1.9    Conclusions

It is BOYD’s overall conclusion that U.S. Silica’s estimates of proppant sand reserves, as reported herein: (1) were prepared in

conformance with accepted industry standards and practices, and (2) are reasonably and appropriately supported by technical

evaluations, which consider all relevant modifying factors.

Given the operating history and status of evolution, residual uncertainty (future risk) for this operation is considered minor under the

current and foreseeable operating environment. It is BOYD’s opinion that extraction of the proppant sands reported herein is

technically, legally, and economically achievable after the consideration of potentially material modifying factors. The ability of U.S.

Silica, or any mine operator, to recover all the reported proppant sand reserves is dependent on numerous factors that are beyond

the control of, and cannot be anticipated by, BOYD. These factors include mining and geologic conditions, the capabilities of

management and employees, the securing of required approvals and permits in a timely manner, future proppant sand prices, etc.

Unforeseen changes in regulations could also impact performance.

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JOHN T. BOYD COMPANY

2-1

2.0    INTRODUCTION

2.1    Registrant

U.S. Silica is a US-based mining company headquartered in Katy, Texas. The company’s common stock is listed on the New York

Stock Exchange (NYSE:SLCA). U.S. Silica is actively engaged in the production and marketing of commercial silica sand and

performance materials (diatomaceous earth, calcium bentonite clay, calcium montmorillonite clay, and perlite products). Their whole

grain silica products are used as proppant (frac) sand for oil and natural gas recovery, and in the manufacture of glass, foundry, and

building products. U.S. Silica’s performance materials are used in: (1) filtration for foods and beverages, pharmaceuticals, and

swimming pools; (2) as additives in paint and coatings, plastics and rubber, and agriculture products; and (3) for bleaching, catalysis

and adsorption in edible oil processing, aromatics purification, and industrial and chemical applications. Additional information

regarding U.S. Silica can be found on their website: www.ussilica.com.

2.2    Terms of Reference and Purpose

U.S. Silica retained BOYD to complete an independent technical assessment of their internally-prepared proppant sand resource

and reserve estimates and supporting information for the Crane Operation.

BOYD prepared this technical report summary for U.S. Silica in support of their disclosure of proppant sand reserves for the Crane

Operation in accordance with S-K 1300. The purpose of this report is threefold: (1) to summarize material technical and

geoscientific information for the subject mining property, (2) to provide the conclusions of our technical assessment, and (3) to

provide a statement of proppant sand resources and/or reserves for the Crane Operation.

BOYD’s findings are based on our detailed examination of the supporting geologic and other scientific, technical, and economic

information provided by U.S. Silica, as well as our assessment of the methodology and practices applied by U.S. Silica in

formulating the estimates of proppant sand resources and reserves disclosed in this report. We did not independently estimate

proppant sand resources or reserves from first principles.

We used standard engineering and geoscience methods, or a combination of methods, that we considered to be appropriate and

necessary to establish the conclusions set forth herein. As in all aspects of mining property evaluation, there are uncertainties

JOHN T. BOYD COMPANY

2-2

inherent in the interpretation of engineering and geoscience data; therefore, our conclusions necessarily represent only informed

professional judgment.

The ability of U.S. Silica, or any mine operator, to recover all of the estimated proppant sand reserves presented in this report is

dependent on numerous factors that are beyond the control of, and cannot be anticipated by, BOYD. These factors include mining

and geologic conditions, the capabilities of management and employees, the securing of required approvals and permits in a timely

manner, future sand prices, etc. Unforeseen changes in regulations could also impact performance. Opinions presented in this

report apply to the site conditions and features as they existed at the time of BOYD’s investigations and those reasonably

foreseeable.

This report is intended for use by U.S. Silica, subject to the terms and conditions of its professional services agreement with BOYD.

We also consent to U.S. Silica filing this report as a technical report summary with the SEC pursuant to S-K 1300. Except for the

purposes legislated under US securities law, any other uses of or reliance on this report by any third party is at that party’s sole risk.

2.3    Expert Qualifications

BOYD is an independent consulting firm specializing in mining-related engineering and financial consulting services. Since 1943,

BOYD has completed over 4,000 projects in the United States and more than 60 other countries. Our full-time staff comprises

mining experts in: civil, environmental, geotechnical, and mining engineering; geology; mineral economics; and market analysis. Our

extensive experience in proppant sand resource and reserve estimation combined with our knowledge of the subject property,

provides BOYD an informed basis on which to opine on the reasonableness of the estimates provided by U.S. Silica. An overview of

BOYD can be found on our website at www.jtboyd.com.

The individuals primarily responsible for completing this technical assessment and the preparation of this report are by virtue of their

education, experience, and professional association considered qualified persons (QPs) as defined in S-K 1300.

Neither BOYD nor its staff employed in the preparation of this report have any beneficial interest in U.S. Silica, and are not insiders,

associates, or affiliates of U.S. Silica. The results of our assessment were not dependent upon any prior agreements concerning the

conclusions to be reached, nor were there any undisclosed understandings concerning any future business dealings between U.S.

Silica and BOYD. This report was

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prepared in return for fees based upon agreed commercial rates, and the payment for our services was not contingent upon our

opinions regarding the project or approval of our work by U.S. Silica and its representatives.

2.4    Principal Sources of Information

Information used in this assignment was obtained from: (1) files provided by U.S. Silica, (2) discussions with U.S. Silica personnel,

(3) records on file with regulatory agencies, (4) public sources, and (5) nonconfidential information in BOYD’s possession.

The following information was provided by U.S. Silica:

• Year-end reserve statements and reports for 2021 and 2022.
• Exploration records (e.g., drilling logs and lab sheets).
• Geologic databases of lithology and sand quality.
• Computerized geologic models.
• Mapping data, with:

Land ownership boundaries.
Infrastructure locations.

-
-
- Easement and right-of-way boundaries.
- Surveyed topography (surface elevation).

• Mine plans, production schedules, and supporting data.
• Overview of processing operations and detailed flow sheets.
• Copies of mining and operating permits.
• Historical information, including:

- Production reports.
-
Financial statements.
- Product sales and pricing.

Information from sources external to BOYD and/or U.S. Silica are referenced accordingly.

The data and work papers used in the preparation of this report are on file in our offices.

2.5    Personal Inspections

A site visit and inspection of the Crane Operation was completed on October 25, 2022,

by BOYD’s QPs responsible for the preparation of this report. The site visit included: (1) observation of the active mining operations,

(2) a tour of the mine site’s surface infrastructure, and (3) a tour of the process plant and truck loadouts. BOYD’s representatives

were accompanied by senior U.S. Silica engineering and management

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personnel who openly and cooperatively answered questions regarding, but not limited to: site history; deposit geology; mining and

processing operations; near- and long-range mining plans; and proppant sand marketing.

2.6    Report Version

The proppant sand resources and reserves presented in this Technical Report Summary are effective as of December 31, 2022.

The effective (i.e., “as of”) date of the report is December 31, 2022.

This is the first Technical Report Summary filed by U.S. Silica for the Crane Operation. The user of this document should ensure

that this is the most recent disclosure of proppant sand resources and reserves for the Crane Operation as it is no longer valid if

more recent estimates have been issued.

2.7    Units of Measure

The US customary measurement system has been used throughout this report. Tons are short tons of 2,000 pounds-mass. Unless

otherwise stated, currency is expressed in US Dollars ($). Historic prices and costs are presented in nominal (unadjusted) dollars.

Future dollars values are expressed on a constant (unescalated) basis.

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3.0    PROPERTY DESCRIPTION

3.1    Location

U.S. Silica’s Crane Operation is a surface proppant sand mining and processing operation located 25 miles west of the City of

Odessa in Crane County, Texas. The cities of Lubbock and Dallas, Texas, are located approximately 147 miles northeast and 355

miles east, respectively, of the Crane Operation. Figure 1.1 (page 1-2) illustrates the general location of the Crane Operation.

The property is contiguous with the exception of pre-existing oil production infrastructure easements for roads, storage areas,

pipelines and pump jack stations. The mine offices, maintenance facilities, processing plant, loadout facilities, and former mining pits

are located on the northeast edge of the property. Figure 3.1, on the following page, shows the general layout of the Crane

Operation.

Geographically, the Crane Operation’s processing plant is located at approximately 31° 38' 58.34" N latitude and 102° 42' 2.52" W

longitude.

3.2    Property Rights

The Crane Operation comprises approximately 3,200 acres of surface and minerals rights fully owned by U.S. Silica. The land with

mineral rights was purchased by U.S. Silica for the purposes of developing a new proppant sand mine in the Permian Basin.

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3.3    Encumbrances

3.3.1    Fees and Royalties

To maintain ownership of the Crane Operation property, U.S. Silica must pay property taxes to the local government in Crane

County. To BOYD’s knowledge, there are no liens against the properties.

The purchase agreement for the property included a royalty payable to the sellers (McKnight Natural Resources and Flying U

Properties). The royalty rate is $1.00 per ton of processed proppant sand sold.

It is BOYD’s understanding that there are no additional royalties, overriding or limited royalties, working interests, production

payments, net profit interests, or other mineral interests in the Crane Operation properties.

3.3.2    Permitting Requirements

Mining and processing activities on the Crane Operation properties are regulated by several federal and state laws. As mandated by

these laws and regulations, numerous permits are required for mining, processing, and other incidental activities. U.S. Silica reports

that necessary permits are in place or applied for to support immediate operations. New permits or permit revisions may be

necessary from time to time to facilitate future operations. Given sufficient time and planning, U.S. Silica should be able to secure

new permits, as required, to maintain its planned operations within the context of the current regulations. Permitting and permitting

conditions are discussed further in Chapter 17 of this report.

In BOYD’s opinion, U.S. Silica has demonstrated their ability and cooperation to align their operating plans with any permitting

requirements that may be encountered during the normal course of business.

BOYD is not aware of any current material violations or fines imposed by regulators on the Crane Operation.

3.3.3    Mining Restrictions

Several natural and man-made features have been identified in and around the Crane Operation which may limit the mineable

areas of the property. As of this report, these features include:

• Setbacks from neighboring properties.
• Setbacks from oil production infrastructure.
• Setbacks from existing utility corridors.

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U.S. Silica has included suitable setbacks in their mining plans to avoid disturbing these sensitive areas. As such, these areas have

been excluded from the estimates of proppant sand resources and reserves presented herein.

3.3.4    Other Significant Factors or Risks

To the extent known to BOYD, there are no other significant factors and risks that may affect access, title, or the right or ability to

perform work on the Crane Operation property that are not discussed in this report. However, the reported proppant sand resources

and reserves may be materially impacted by: U.S. Silica’s failure to comply with permit conditions and rules; delays in obtaining

required government or other regulatory approvals or permits; U.S. Silica’s inability to obtain such required approvals or permits; or

unforeseen changes in governmental regulations.

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4.0    PHYSIOGRAPHY, ACCESSIBILITY, AND INFRASTRUCTURE

4.1    Topography, Elevation, and Vegetation

The Crane Operation lies within the Llano Estacado, the Southern High Plains extension of the Great Plains of North America. This

region is relatively flat, with windblown sand dunes in various locations. The sand deposits at the Crane Operation are locally known

as the Monahans Sandhills.

Surface elevations in and around the property range from approximately 2,705 ft above mean sea-level (AMSL) near the southeast

property corner to over 2,750 ft AMSL on the western edge of the property.

No natural surface waters are present at the Crane Operation.

Land cover in the immediate area consists predominantly of a mixture of shinnery oak, grasses, and other various scrub vegetation.

4.2    Accessibility

General access to the Crane Operation is via a well-developed network of very close proximity primary and secondary roads

serviced by private, state, and local governments. These roads provide direct access to the mine and processing facilities and are

generally open year-round. These roads are a combination of paved and graveled and are well maintained year-round.

4.3    Climate

Climate in and around the Crane Operation is characteristic for the southwest US, with four seasons ranging from mild winters to

very hot and dry summers, with generally moderate falls and springs. The average daily high temperatures typically reach above

freezing all 12 months of the year, while the low temperatures can drop below freezing during four months of the year. Winter

temperatures typically range from 31 degrees Fahrenheit (° F) to 73° F, while summer temperatures usually range from 64° F to 95°

F. Average annual precipitation for the area is approximately 15–20 inches of rain and less than four inches of snow.

In general, the operating season for the Crane Operation is year-round. Adverse weather conditions seldom limit mining,

processing, and loading operations; however, extreme

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weather conditions may temporarily impact operations. Periodic flooding is possible during heavy rainfall.

4.4    Infrastructure Availability and Sources

The Crane Operation lies within a rural region of western Texas and has been operating in a region of heavy oil and gas industry

and agricultural development. The City of Crane has a population of 3,682, and 4,675 people live in Crane County according to

2020 U.S. Census data.

Finished proppant sand products from the Crane Operation are transported to customers by bulk truck and supported by U.S.

Silica’s extensive on-site loading, storage, and handling facility.
Several regional airports are located within an hour’s drive from the Crane Operation, and the Midland International Airport is less

than an hour away by car.

Reliable sources of electrical power, water, supplies, and materials are readily available. Electrical power is provided to the

operation by regional utility companies. Water is supplied by a private water gathering and transportation network, surface

impoundments, or water wells. The Crane Operation has an abundance of recycled processing water available.

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5.0    HISTORY

5.1    Reserve Acquisition

U.S. Silica purchased the Crane property in May 2017 from the McKnight Natural Resources and Flying U Properties after

completing an initial reconnaissance-level exploration drilling campaign on the subject property.

U.S. Silica is the first landowner to mine proppant sand at this location. Other than sparse agricultural activity and various oil and

gas infrastructure, previous landowners have not developed the site. No known mining-related exploration work had been

performed prior to U.S. Silica ownership.

5.2    Mine Development
The Crane property was purchased by U.S. Silica to service the booming oil and gas industry in the Permian Basin. Prior, most

proppant sand was imported from out-of-state. In order to lower operational costs in the oil and gas industry, companies began
looking at developing local sources of proppant sands. U.S. Silica has developed several proppant sand sites in the west Texas
area, including the Crane Operation.

Prior to the property acquisition, a two-phase rotosonic exploration program referred to as “Project Thunderhead” was completed in

March-April 2017, consisting of 25 rotosonic drill holes being completed between 15–65 ft in depth.

Plant construction commenced shortly after purchasing Crane, and first sales from the operation occurred by mid-2018.

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6.0    GEOLOGICAL SETTING, MINERALIZATION, AND DEPOSIT

6.1    Regional Geology

The Crane Operation is located within the Llano Estacado, situated in the Texas High Plains. This region comprises the southern-

most portion of the Great Plains, which extends into northeastern New Mexico and northwestern Texas. The Llano Estacado forms

a vast elevated plain (high mesa) that is almost completely covered with sand deposits of various types. In the region, the ground

surface is covered by windblown sheet sands and active sand dunes reaching heights of almost 45 ft.

The Crane Operation is also located near the central portion of the Permian Basin, which is well known for its long-producing

petroleum and natural gas fields. While the subject of this report concentrates on the surficial geology (sand deposits) of west

Texas, the Crane Operation currently sells its proppant sand products to the oil and gas producers working in the Permian Basin.

6.2    Local Geology

6.2.1    General Stratigraphy

Surficial geologic units overlying the area in and around the Crane Operation are predominantly comprised of undifferentiated

Quaternary Age unconsolidated deposits, ranging from aeolian (windblown) sheet sands and dunes to alluvial sands, silts, clays,

and caliche. Geologic mapping shows additional surficial stratigraphic units present in the vicinity of the project; however, the

surface geology in and around the Crane Operation is primarily comprised of these aeolian sand deposits.

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A generalized stratigraphic chart of the geologic units in Crane County, Texas is presented in Figure 6.1.

6-2

Exploration completed on the Crane property indicate two surficial sand units being present, an upper clean sand unit (dune and

sheet sands) and an underlying clayey cover sand unit (Judkins Formation). The following text discusses the strata encountered in

and around the Crane Operation, in depositional order:

Fredericksberg Group

A thick unit of limestone, dolomite, marl, and caliche, which represents the basal unit encountered at the Crane Operation. An

unconformity separates this unit from the overlying Judkins formation, which differs significantly in age.

Judkins (Blackwater Draw Equivalent) Formation

The Judkins Formation is a brownish-red, argillaceous (clay-rich) sand body consisting of fine- to medium-grained quartz which may

be silty and calcareous. This formation represents the first major period of dune building to affect the area and includes minor

amounts of interdune pond sediments.

Quaternary Sheet and Dune Sands

Most of the subject property is covered by Quaternary sheet and dune sands generally consisting of fine- to medium-grained quartz

sand grains, mixed with varying degrees of clays and silts.

General geologic descriptions from the Crane County area also indicate some local Quaternary deposits may also include gravel or

be locally indurated with calcium carbonate (caliche). These deposits are the result of various geologic processes during

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deposition, such as the formation of levees, point bars, stream channels, alluvial fans, and terrace or playa deposits.

6.2.2    Structural Geology

The structural features of the Quaternary sands in and around the Crane Operation are relatively non-descript. While the unit

exhibits variable thickness over the area, it is unaffected by folding or faulting. Underlying the surficial sand units is the limestone

basal unit, which defines the mineable limit of the sands on and around the subject property. Due to the lack of structural features

encountered, there are no known geological features that are believed to materially affect a proppant sand mining operation in the

immediate area; as such, the deposit is considered to be of low geologic complexity.

6.3    Property Geology

As described above, surficial geologic units overlying the Crane Operation are predominantly comprised of undifferentiated

Quaternary age unconsolidated deposits, ranging from aeolian (windblown) sheet sands and dunes to alluvial sands, silts, clays,

and caliche. The top 12 in. of the sand unit is generally contaminated with surface debris and organic content and is considered

overburden. Figure 6.2 (page 6-5) provides a map of the sand thickness. A cross-section through the deposit is provided in Figure

6.3 (page 6-6).

The surface sands on the property consist of two distinct intervals that are both mineable sand: 1) an upper loose sand unit, and 2)

a lower “sandstone” unit. Underlying the total mineable surface sand deposits is the hard, limestone basal unit which commonly

results in the presence of caliches. The upper sand as generally consisting of unconsolidated, fine- to medium-grained, well sorted

and subangular to rounded sand grains, ranging in thickness from 13 to 46 ft. The clean sand is noted as containing generally less

than 15% fine (clay) material. The lower sand is described as a clayey, hard sandstone interval, with very fine- to medium-grained,

subangular to rounded sand grains, ranging in thickness from 0 to 25 ft. The lower sand is noted having a higher (15–45%) clay

content. The two sand units are generally mineable from the ground surface down to the basal limestone unit. Combined thickness

of both sand units ranges from 10 to 80 ft across the property.

The sand mined at the Crane Operation is processed to produce proppant sand. Proppant sand is a naturally occurring, high silica

content quartz sand with grains that are generally well-rounded. The main difference between proppant sand and other sands is that

proppant sand grains are relatively pure in composition and consisting

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almost entirely of quartz; other sands have numerous impurities that may be cemented to the quartz grains. The pure quartz

composition of proppant sand grains, along with being well-rounded and spherical in shape, gives these sands the characteristics

(crush strength, high acid solubility, low turbidity) that are sought after by oil and gas producers for use in developing wells.

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7.0    EXPLORATION DATA

7.1    Background
In developing the Crane Operation, U.S. Silica has completed two different exploration campaigns. Records from these campaigns

were provided and comprise the primary data used in the evaluation of the proppant sand resources. A total of 26 drill holes
(totaling 1,003 ft of drilling) are distributed across the property and their results have been compiled into a database. Maps
illustrating the extents of the sand deposit, electronic copies of drilling and sampling logs, as well as laboratory testing summaries,
were provided for our review.

7.2    Exploration Procedures

U.S. Silica provided BOYD with various information including exploration reports and internal guidelines, regarding drilling,

sampling, and testing procedures utilized during the two exploration campaigns completed on the Crane property.

7.2.1    Drilling

To date, U.S. Silica has performed two drilling campaigns on the Crane property. Both campaigns were completed by third-party

contractors using rotosonic (sonic drilling) equipment. Sonic drilling methods are widely accepted as one of the best methods to

recover core when exploring unconsolidated sand deposits.

Phase 1 Exploration Campaign

U.S. Silica completed a preliminary reconnaissance-level exploration campaign at the Crane Operation in March 2017. The purpose

of this campaign, known as the Kermit/Gallop portion, was to gain an initial understanding of the potential quantity and quality of the

dune sand deposit on the property, and to delineate the extents of the potentially mineable sand, by areal extent and depth.

Drilling was planned and supervised by U.S. Silica’s Mine Planning Department, who also conducted core logging and sampling in

the field. Cascade Environmental, LLC was contracted to conduct drilling in this phase of drilling, with a total of 16 rotosonic drill

holes completed. The completed drill holes were laid out in a general east-west trending line across the areas of the property

containing sand dunes.

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Phase 2 Exploration Campaign

After the initial phase of exploration and testing provided positive results, a second infill drilling campaign was planned and

completed in April 2017. This campaign, known as Outpost, consisted of completing 10 additional rotosonic drill holes at the Crane

Operation. Focus was placed on maximizing the potential of Proven and Probable reserves and obtaining enough additional data to

begin mine planning exercises.

U.S. Silica contracted Associated Environmental Industries, Corp. (AEI) to complete the rotosonic drilling for Phase 2, and hired a

contract geologist from Summit Envirosolutions, Inc. to log and sample core and supervise this phase of exploration work. After

completing Phase 2 drilling, U.S. Silica utilized all of the site-specific data thus far to complete an initial proppant sand reserve

estimate, and subsequently finalized the purchase of the Crane Operation in July 2017.

7.2.2    Sampling Procedures

Records indicate the drill core was measured and geologically logged before being boxed and transported to U.S. Silica’s in-house

laboratory in Berkeley Springs, West Virginia. At the lab, sample composites were created by reviewing geologic logs, and then

splitting and thoroughly mixing the desired composite intervals to create homogenous and representative samples for testing

purposes.

U.S. Silica maintained control of exploration core samples throughout the entirety of each drilling campaign from the point of logging

and boxing of recovered cores in the field to transportation and delivery of core samples to their internal laboratories through the

preparation and analyses on each of the samples.

Available testing results were reviewed by BOYD during our assessment, and our review of the field and sampling procedures

indicated that the general description and sampling work were conducted to appropriate standards. Based on the stated standards,

both in the field and in the laboratory, BOYD concludes that the sample preparation and analytical procedures were adequate for the

purposes of evaluating and estimating proppant sand resources and reserves at the Crane Operation.

7.2.3    Sand Testing
Samples obtained from the exploration campaigns were taken to the company’s 

in-house laboratory where they were inventoried and then prepared for analyses. Samples were split and prepared following

standardized company procedures (i.e., U.S. Silica’s ISO 9001 Quality System of Corporate Analytical Procedures) to ensure

analytical consistency throughout each exploration campaign. These procedures are

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designed to closely match the operational capabilities of the Crane Operation’s processing plant.

Preparation of each sample consisted of initially splitting the recovered core in half. One half of the core is placed back into the core

boxes which are then stored for archival purposes, while the other half of the core is further prepared and processed for lab testing

purposes.

Analytical samples were crushed, quartered, and mixed to create a uniform and representative composite of the core interval, and

then the composite sample was divided into appropriately sized samples depending on the type and amount of testing to be

performed. The sample is then run through various crushing techniques to disaggregate the sand grains and fine materials as much

as possible before beginning the washing and scrubbing procedures.

After splitting, the sample is dried, and an approximately 1,500-gram split is obtained. The sample split is washed through a 200-

mesh sieve to remove slimes, before being dried and reweighed to measure the recovery of plus-200-mesh material. The dried

sample is then run through a 16-mesh sieve to simulate the scalping procedure in the plant to remove the “coarse waste” sized

particles. The remaining material is then approximately equivalent to the material that would typically be washed in the wet

processing plant. This remaining material is weighed and labeled as a prepared “washed sample”.

The washed sample is further prepared by simulating the wet processing plant conditions, which consist of placing the sample into

scrubbers for three minutes, rinsing and decanting, and then drying to arrive at a “scrubbed sample”, which represents material that

would be output from the wet processing plant. The scrubbed samples are then dried and prepared for API RP 19C/ISO-13503-2

standard testing for proppant materials.

7.2.4    Other Exploration Methods

There were not any other methods of exploration (such as airborne or ground geophysical surveys) reported for the Crane

Operation.

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7.3    Exploration Results

7.3.1    Summary of Exploration

Exploration work to date has resulted in a total of 26 drill holes completed in and around the Crane property, through the course of

two separate exploration campaigns. Information obtained from the exploration campaigns indicates U.S. Silica identified a clean

surface sand unit that consists of recently active sand dunes which overlies a separate clayey-sand unit containing older and more

variable depositional sequences. Both of these sand intervals are mined together at the Crane Operation.

The overall drill hole spacing exhibited across a majority of the subject property ranges from approximately 1,300 ft to 5,000 ft. The

distribution of these drill holes is illustrated on Figure 7.1, following this page.

Data collected as a result of completing these drilling campaigns highlights some of the variability of the lithologic nature of the

deposit underlying the Crane property. However, looking at the overall mineable interval; overall trends show the mineable interval

generally getting thicker towards the west-southwest portions of the property. The data obtained on the total mineable sand unit

supports the general interpretation of the sandstone’s thickness, as illustrated in Figure 6.2 (page 6-5).

BOYD’s review of the reported sampling methodology and procedures provided indicate the data obtained by U.S. Silica for the

Crane Operation was carefully and professionally collected, prepared, and documented in conformance with generally accepted

industry standards, and are appropriate for use of evaluating and estimating frac sand resources and reserves.

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7.3.2    Sand Quality
The Crane Operation produces two varieties of proppant sand for use in local oil and gas applications: a 40/70-mesh proppant sand

product and a 100-mesh proppant sand product. U.S. Silica performs testing at their laboratories for API/ISO specifications.

Historically, API RP 19C/ISO 13503-2 proppant sand characteristics were strictly adhered to in order to determine the suitability of a

sand product for use during fracking stages of oil and gas well development. Over time, these specifications have become merely

guidelines, and the suitability of a proppant sand product is now ultimately determined by customers, who will typically perform their

own sample testing of the products that they purchase to determine if they meet their internal specifications.

BOYD notes that U.S. Silica has demonstrated continued commercial success in producing and marketing the finished proppant

sand products; as such, it is BOYD’s opinion that sand quality data provided are representative of the mined deposit and are

considered suitable for the estimation of proppant sand resources and reserves.

7.3.3    Grain Size Distribution

Grain size distribution was analyzed according to API RP 19C/ISO 13503-2, Section 6.

A table of weighted average grain size distribution of the in-situ sand deposit, based on laboratory testing results, is shown in Table

7.1, below.

The preceding table highlights the relative fineness of the sand found at the Crane Operation; indicating a majority of the sand

particles are concentrated between the “passing 40-mesh” and “retained 140-mesh” size fraction. Accordingly, the predominant

marketable proppant sand product consists of the 40/140-mesh sand.

Grain Shape (Sphericity and Roundness)

Grain shape is defined under API RP19C/ ISO 13503-2, Section 7. Under this standard, recommended sphericity and roundness

values for proppants are 0.6 or greater. As part of the grain shape analysis, the presence of grain clusters (weakly cemented grain

aggregates) and their approximate proportion in the sample are reported.

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Crush Resistance

Crush resistance is a key test that determines the amount of pressure a sand grain can withstand under laboratory conditions for a

two-minute duration. It is analyzed according to API RP19C/ ISO 13503-2, Section 11. Under this standard, the highest stress level

(psi) in which the proppant produces no more than 10% crushed fine material is rounded down to the nearest 1,000 psi and

reported as the “K-value” of the material.

Acid Solubility

Acid solubility was analyzed according to API RP19C/ ISO 13503-2, Section 8. Under this standard, 5 grams of sand is treated with
o
100 milliliters of 12:3 hydrochloric acid to hydrofluoric acid at 150 F for 30 minutes. The recommended maximum acid solubility for

proppants in the 40/70 size range and finer is 3.0%.

Turbidity

Turbidity was analyzed according to API RP19C/ ISO 13503-2, Section 9. Under this standard, the suggested maximum frac sand

turbidity should be equal to or less than 250 nephelometric turbidity units (NTU).

Results from these analyses are shown below in table 7.2:

The composite sample testing suggests the Crane Operation can produce proppant sands which meet minimum API/ISO

recommended specifications. Moreover, U.S. Silica has a demonstrated commercial success producing and selling proppant sand

to Permian Basin oil and gas producers, where ultimately the sand has been shown to meet customer specifications.

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7.4    Data Verification

For purposes of this report, BOYD did not verify historic drill hole data by conducting independent drilling. It is customary in

preparing similar mining resource and reserve estimates to accept basic drilling and sample quality data as provided by the client,

subject to the reported results being judged representative and reasonable.

BOYD’s efforts to judge the appropriateness and reasonability of the source exploration data included reviewing representative

samples of provided drilling logs, sampling procedures, sand quality testing results, and discussing aspects of developing the Crane

Operation with U.S. Silica personnel during our site visit. Reviewed drilling records were compared with their corresponding

database records for transcription errors; of which none were found. Lithologic and sand quality data points were compared via

visual and statistical inspection with geologic mapping and cross-sections.

7.5    Adequacy of Exploration and Sampling

BOYD’s review of the reported methodologies and procedures indicate the exploration data obtained and utilized by U.S. Silica for

the Crane Operation were: (1) carefully and professionally collected, prepared, and documented, (2) conform with general industry

standards, and (3) are appropriate for use of evaluating and estimating proppant sand resources and reserves. Similarly, BOYD’s

review of testing data provided by U.S. Silica suggests that the analyses completed are generally appropriate to determine proppant

sand characteristics and determine the subsequent quality of finished proppant sand products. As such, it is BOYD’s opinion that

the exploration and sampling data are suitable for use in the estimation of proppant sand resources and reserves for the Crane

Operation.

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8.0    SAMPLE PREPARATION, ANALYSIS, AND SECURITY

The reader is referred to Sections 7.3 and 7.4 of this report for details regarding sample preparation, analysis, and security.

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9.0    DATA VERIFICATION

BOYD, by way of the data verification processes described in various sections of this report, has used only that data deemed by the
QPs to have been generated with proper industry standard procedures, were accurately transcribed from the original source, and

were suitable to be used for the purpose of preparing estimates of proppant sand resources and reserves.

BOYD’s subject-specific data verification efforts and our conclusions arising therefrom are discussed in the following sections of this
report:

Based on our review, it is BOYD’s overall conclusion that the information made available to us at the time of this report is
representative and reliable for use in estimating the proppant sand resources and reserves of the Crane Operation.

BOYD is not aware of any other limitations on nor failure to conduct appropriate data verification.

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10-1

10.0    MINERAL PROCESSING AND METALLURGICAL TESTING

Please refer to Chapter 7 for information regarding grain size distribution and proppant sand characteristics testing.

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JOHN T. BOYD COMPANY

11-1

11.0    PROPPANT SAND RESOURCE ESTIMATE

11.1    Applicable Standards and Definitions

Unless noted, proppant sand resource estimates disclosed herein are done so in accordance with the standards and definitions

provided by S-K 1300. It should be noted that BOYD considers the terms “mineral” and “proppant sand” to be generally

interchangeable within the relevant sections of S-K 1300.

Estimates of mineral resources are always subject to a degree of uncertainty. The level of confidence that can be applied to a

particular estimate is a function of, among other things: the amount, quality, and completeness of exploration data; the geological

complexity of the deposit; and economic, legal, social, and environmental factors associated with mining the resource. By

assignment, BOYD used the definitions provided in S-K 1300 to describe the varying degree of certainty associated with the

estimates reported herein.

The definition of mineral resource provided by S-K 1300 is:

Mineral resource is a concentration or occurrence of material of economic interest in or on the Earth's crust in such form,
grade or quality, and quantity that there are reasonable prospects for economic extraction. A mineral resource is a
reasonable estimate of mineralization, taking into account relevant factors such as cut-off grade, likely mining dimensions,
location or continuity, that, with the assumed and justifiable technical and economic conditions, is likely to, in whole or in part,
become economically extractable. It is not merely an inventory of all mineralization drilled or sampled.

Estimates of mineral resources are subdivided to reflect different levels of geological confidence into measured (highest geologic

assurance), indicated, and inferred (lowest geologic assurance). Please refer to the Glossary of Abbreviations and Definitions for

the meanings ascribed to these terms.

JOHN T. BOYD COMPANY

11-2

11.2    Proppant Sand Resources

11.2.1    Methodology

Based on provided information, U.S. Silica’s geologic modeling and proppant sand resource estimation techniques generally consist

of following:

1. The top and bottom elevations of the mineable proppant sand interval is interpreted from drill hole records and sand particle size

analyses. The sands mined at the Crane Operation are present at the surface. The uppermost 12 in. of the sand unit is
considered overburden since it is generally contaminated with surface debris and organic matter. Strata below the sand unit—
generally, the limestone basal unit—are considered waste.

2.

Interpreted drill hole records are compiled and validated. Strata thicknesses are aggregated, and sand particle size analyses of
the sand unit are composited for each data point. The compiled drill hole data are imported into GEOVIA Surpac™ geologic
modeling and mine planning software.

3. A geologic block model of the deposit is developed using industry standard stratigraphic modeling methods. The geologic model

delineates the top and bottom of the mineable sand horizon.

4. Contiguous regions of mineable sand are outlined (applying criteria discussed below in Section 11.2.2), and LOM pit shells are

created.

5. Estimates of in-place mineable sand volumes are derived from the LOM pit shells and recent topographic (surface elevation)

survey elevations.

6. An in-place dry density of 100 pounds per cubic foot is used to convert the in-place sand volumes to in-place sand tons.

11.2.2    Estimation Criteria

Development of the proppant sand resource estimate for the Crane Operation assumes mining and processing methods and

equipment which have been utilized successfully at the site for decades.

The target surface sand mining horizon at the Crane Operation is manifested as continuous low rolling sand dunes overlying an

older sand dune complex. The sand unit exhibits relatively consistent depth, thickness, and quality. The sand interval is easily

distinguished from the underlying limestone unit; aiding in the interpretation of the mineable horizon. Generally, all of the sand unit is

mined and sold under various product specifications. Based on the uniformity of the sand deposit being mined, cut-off grade, strip

ratios, and other typical mining factors do not define economic mineability. Production of proppant sand is driven by market demand

and production can be modified in response to that demand. As such, the application of minimum mining thicknesses, maximum

stripping ratios (the ratio of waste to sand excavated), or cut-off

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grades is not generally considered in the estimation of proppant sand resources for the Crane Operation.

The limits of the proppant sand resources are constrained to those portions of the interpreted sand deposit that:

• Are reasonably defined by available drilling and sampling data.

• Contain products that meet generally accepted specifications.

• Honor any legal mining constraints (e.g., property boundaries, environmental setbacks, utility and infrastructure setbacks, etc.).

• Adhere to physical mining constraints.

• Contain products that can be sold at a profit (i.e., be economic).

U.S. Silica applied the following offsets to define the proppant sand resource boundaries for the Crane Operation:

•
•

100-ft offsets from neighboring property boundaries.
200-ft right-of-ways around roadways, oil and gas pipelines, and utility corridors.

The pits shells which constrain the estimated proppant sand resources utilized overall wall slope of 3:1 (horizonal to vertical) in

unconsolidated sand. There were not any other pit design criteria employed.

Proppant sand resources for the Crane Operation are assessed for reasonable prospects for eventual economic extraction by

reporting: (1) only those resources which have been subsequently converted to proppant sand reserves after the application of all

material modifying factors, or (2) those resources which have similar characteristics (i.e., mining conditions, and expected product

yields and qualities) to those converted to proppant sand reserves.

BOYD has reviewed the criteria employed by U.S. Silica in developing their estimates of proppant sand resources. The parameters

are supported by historical results and align with those employed at similar operations. As such, it is BOYD’s opinion that the stated

criteria are reasonable and appropriate for the estimation of proppant sand resources at the Crane Operation.

11.2.3    Classification

Geologic assuredness is established by the availability of both structural (thickness and elevation) and particle size distribution for

the proppant sand. Classification is generally

JOHN T. BOYD COMPANY

11-4

based on the concentration or spacing of exploration data, geological understanding, continuity of mineralization relative to the style

of mineralization, and uncertainty with the exploration data.

Table 11.1 provides the general criteria employed in the classification of the proppant sand resources.

Extrapolation or projection of resources in any category beyond any data point does not

exceed half the point spacing distance.

BOYD reviewed the classification criteria employed by U.S. Silica with regards to data density, data quality, geological continuity

and/or complexity, and estimation quality. The surficial sand dune deposit on the Crane property is of low geologic complexity. We

believe these criteria appropriately reflect their implied levels of geologic assurance with respect to the estimation of proppant sand

resources.

Mineable sand resources on the property are well-defined throughout all areas of the mine plan. Observed drill hole spacing ranges

from 1,300 to 5,000 ft across the defined resource area.

JOHN T. BOYD COMPANY

11-5

11.2.4    Proppant Sand Resource Estimate

Resource estimates of in-place proppant sand at the Crane Operation as of December 31, 2022, reported by U.S. Silica are shown

in Table 11.2, below.

As shown, U.S. Silica controls approximately 157.8 million in-place tons of measured and indicated proppant sand resources,

inclusive of proppant sand reserves. In addition, they control approximately 16.4 million in-place tons of inferred proppant sand

resources. Proppant sand resources are not proppant sand reserves and do not have demonstrated economic viability.

The proppant sand resources shown under the “Planned” column of Table 11.2 include only those in-place tons which are included

in U.S. Silica’s LOM plan for the Crane Operation and therefore considered for conversion to proppant sand reserves. The proppant

sand resources shown under the “Additional” column of Table 11.2 have not been included in the LOM plan and are considered

exclusive of (i.e., “in addition to”) the reported proppant sand reserves. These “Additional” proppant sand resources are considered

to have prospects for eventual economic extraction by virtue of their similarity, in terms of demonstrated extraction methods and

expected finished product qualities, to those converted to proppant sand reserves. However, further studies are required to convert

the “Additional” proppant sand resources to proppant sand reserves.

11.2.5    Validation

BOYD was provided with U.S. Silica’s exploration data, geologic models, and volumetric estimates. We have reviewed this

information, on a representative basis, by:

• Verifying the accuracy of geologic model inputs by comparison with drilling logs and laboratory reports.

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• Comparing the geologic model with compiled drilling data.

• Preparing a stratigraphic grid model of the sand unit and independently estimating pit shell volumes.

It is BOYD’s opinion that the geologic model is representative of the informing data and that the data are of sufficient quality to

support the proppant sand resources estimate provided herein. Furthermore, it is our opinion that the resources estimation methods

and criteria employed are both appropriate and reasonable for the deposit type and proposed extraction methods.

BOYD is not aware of any technical, legal, economic, or other relevant factors that could materially affect the proppant sand

resource estimate. The accuracy of the proppant sand resource estimate is, in part, a function of the quality and quantity of

available data and of engineering and geological interpretation and judgment. Given the data available at the time this report was

prepared, the estimates presented herein are considered reasonable. However, they should be accepted with the understanding

that additional data and analysis available after the date of the estimate may result in a change to the current estimate. These

revisions may be material. There is no guarantee that all or any part of the estimated resources will be recoverable.

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12.0    PROPPANT SAND RESERVE ESTIMATE

12.1    Applicable Standards and Definitions

Unless noted, proppant sand reserve estimates disclosed herein are done so in accordance with the standards and definitions

provided by S-K 1300. It should be noted that BOYD considers the terms “mineral” and “proppant sand” to be generally

interchangeable within the relevant sections of S-K 1300.

Estimates of mineral reserves are always subject to a degree of uncertainty. The level of confidence that can be applied to a

particular estimate is a function of, among other things: the amount, quality, and completeness of exploration data; the geological

complexity of the deposit; and economic, legal, social, and environmental factors associated with mining the reserve. By

assignment, BOYD used the definitions provided in S-K 1300 to describe the varying degree of certainty associated with the

estimates reported herein.

The definition of mineral reserve provided by S-K 1300 is:

Mineral reserve is an estimate of tonnage and grade or quality of indicated and measured mineral resources that, in the
opinion of the qualified person, can be the basis of an economically viable project. More specifically, it is the economically
mineable part of a measured or indicated mineral resource, which includes diluting materials and allowances for losses that
may occur when the material is mined or extracted.

Estimates of mineral reserves are subdivided to reflect geologic confidence, and potential uncertainties in the modifying factors, into

proven (highest assurance) and probable. Please refer to the Glossary of Abbreviations and Definitions for the meanings ascribed

to these terms.

JOHN T. BOYD COMPANY

Figure 12.1, below, illustrates the relationship between mineral resources and mineral reserves.

12-2

Figure 12.1: Relationship Between Mineral Resources and Mineral Reserves

By industry convention, proppant sand reserves are presented on two bases: mineable and saleable. Mineable reserves represent

the ROM tonnage available for excavation and processing. Saleable reserves represent the tonnage of finished proppant sand

available for sale after processing the mineable reserves.

12.2    Proppant Sand Reserves

12.2.1    Methodology

Estimates of proppant sand reserves for the Crane Operation are derived contemporaneously with estimates of proppant sand

resources. The Crane Operation utilizes commercially proven mining and processing methods to extract and process proppant sand

from the subject property. The operation’s production plans are revised periodically to assure that the conversion of in-place sand to

saleable product are: (1) in reasonable conformity with present and recent historical operational performance, and (2) reflective of

expected mining and processing operations.

JOHN T. BOYD COMPANY

12-3

To derive estimates of mineable tons and saleable product tons (i.e., proven and probable proppant sand reserves), the following

modifying factors were applied to the in-place measured and indicated proppant sand resources underlying the respective mine plan

areas:

• A 95% mining recovery factor, which assumes that 5% of the mineable (in-place) proppant sand resource will not be recovered
for various reasons. Applying this recovery factor to the in-place resource results in the estimated ROM sand tonnage (i.e., the
mineable proppant sand reserves) that will be delivered to the wet process plant.

• An overall 82.5% processing yield. This factor accounts for removal of out-sized (i.e., larger than 20-mesh and smaller than 140-

mesh) sand and losses in the wet and dry processing plants due to minor inefficiencies.

The overall product yield (after mining and processing losses) for the Crane Operation is estimated at approximately 78.4%. That is,

for every 100 tons of in-place proppant sand, approximately 78 tons will be recovered and sold as product. Mining recovery and

processing yield factors are derived from historical operating results.

Economic availability of the proppant sand reserves is established by the financial analysis presented in Chapter 19. A long-range

average selling price of $23.92 per product ton has been used to estimate proppant sand reserves for the Crane Operation.

12.2.2    Classification
Proven and probable proppant sand reserves are derived from measured and indicated proppant sand resources, respectively, in
accordance with S-K 1300. BOYD is satisfied that the stated proppant sand reserve classification reflects the outcome of technical

and economic studies. Figure 12.2, following this page, illustrates the classification of the proppant sand resources and reserves at
the Crane Operation.

JOHN T. BOYD COMPANY

12-4

12-5

12.2.3    Proppant Sand Reserve Estimate
U.S. Silica’s estimated surface mineable proppant sand reserves for the Crane Operation total 121.9 million saleable product tons,

as of December 31, 2022. The proppant sand reserves reported in Table 12.1, below, are based on the approved LOM
plan which, in BOYD’s opinion, is technically achievable and economically viable after the consideration of all material modifying
factors.

All of the reported proppant sand reserves are wholly owned by U.S. Silica.

The proppant sand reserves of the Crane Operation are relatively well-explored and defined. It is our conclusion that almost 75% of
the stated reserves can be classified in the proven reliability category (the highest level of assurance) with the remainder classified
as probable. Given the geologic continuity and U.S. Silica’s history of mining the proppant sand on similar properties, it is
reasonable to assume that the portion of probable reserves will be converted to proven reserves upon completion of additional
exploration and testing.

U.S. Silica has a well-established history of mining, processing, and selling proppant sand products into various markets. BOYD has
assessed that sufficient studies have been undertaken for the Crane Operation to enable the proppant sand resources to be
converted to proppant sand reserves based on current and proposed operating methods and practices. Changes in the factors and
assumptions employed in these studies may materially affect the proppant sand reserve estimate.

The extent to which the proppant sand reserves may be affected by any known geological, operational, environmental, permitting,
legal, title, variation, socio-economic, marketing, political, or other relevant issues has been reviewed as warranted. It is the opinion
of BOYD that U.S. Silica has appropriately mitigated, or has the operational acumen to mitigate, the risks associated with these
factors. BOYD is not aware of any additional risks that could materially affect the development of the proppant sand reserves.

JOHN T. BOYD COMPANY

12-6

Based on our independent review, we have a high degree of confidence that the estimates shown in this report accurately represent
the available proppant sand reserves controlled by U.S. Silica, as of December 31, 2022.

12.2.4    Reconciliation with Previous Estimates
As this is the first technical report summary filed by U.S. Silica for the Crane Operation, no comparison with previous estimates was
performed.

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13.0    MINING METHODS

13.1    Mining Operations

The sheet sands and sand dunes in and around the Crane Operation are loosely consolidated and overlain by minimal overburden;

characteristics which favor conventional surface mining techniques. Since the target sands formation does not extend below the

water table, the quarry is ‘dry-mined’ using truck and excavator mining methods. Mining occurs in a series of benches arranged in a

stair-like fashion to recover sand from the top of the formation (in elevation) down to the lowest practical elevation (generally 1 to 2 ft

above the basal limestone unit).

In some areas of the deposit, the sand is overlain by up to 20 ft of caliche overburden which must be stripped prior to sand mining.

An outside contractor is used to perform this work on an as needed basis. Generally, though, overburden at the Crane Operation is

very thin and not stripped prior to sand excavation. Any vegetation, oversize material or clay that is present is removed at the

processing plant using screens and scrubbers. Oversize material and vegetation are stored at the dry tailings stockpile for use in

future reclamation.

Drilling and blasting are not required for the loosely compacted sand. Excavators and front-end loaders are used to load articulated

haul trucks which transport the sand to a ROM stockpile near the wet process plant. Usually, the sand horizon is mined in a single

30-ft vertical bench. If the depth of the deposit exceeds 30 ft, a second lower bench is mined down to the top of the underlying

limestone. The ROM sand recovered from these two benches are blended at the wet feed plant stockpile to maximize sand

recovery. Figure 13.1, on the next page, shows the current active mining face at the Crane Operation.

JOHN T. BOYD COMPANY

These surface mining techniques have been utilized at the Crane Operation since it began production in 2018. The mining

operations are typically conducted year-round.

13-2

13.2     Mine Equipment and Staffing

13.2.1     Mine Equipment

The primary mobile equipment involved in sand excavation includes:

Front End Loaders.
•
• Caterpillar Excavators.
• Articulated haul trucks.
• Dozer.
• Water Truck and other ancillary equipment.

The mobile equipment fleet is owned and operated by an outside contractor. Regular and major repair maintenance is the

responsibility of the contractor.

If maintained in good condition, the mobile equipment fleet should be capable of achieving production levels required by the LOM

plan.

JOHN T. BOYD COMPANY

13.2.2     Staffing

The Crane Operation is staffed by 85 hourly and salaried personnel.

13-3

Except for a drop in employment in 2020 (attributed to the closure of the Crane Operation due to poor market conditions

experienced during the COVID pandemic), staffing levels across the operational sites have largely been increasing. The workforce

can be expanded or reduced based on market and seasonal demands.

13.3     Engineering and Planning

The primary mine planning consideration is the safe, economical, and regular supply

of raw high-quality sand feed to the processing plant. In commercial mining terms, the quantities of overburden removed, and sand

mined each year at the Crane Operation are considered modest. The sand deposit affords easy access with its shallow depth and

large areal extent. As such, mining plans for the Crane Operation are relatively simple and very flexible; able to be modified based

on demand in a relatively short time frame.

Geotechnically, the sand deposit is relatively competent and the mining depths so shallow such that slumping, or collapsing, has not

been a detriment to the mining process. The pit design parameters discussed in Section 11.2.2 have been used with success at

similar proppant sand operations for decades.

Excessive inflow of groundwater into the pit is not expected. As such, dewatering before or during mining activities should be

manageable with drainage ditches and sumps. Flood waters from localized flash floods are a manageable risk. Onsite water ponds

can be used to hold any excessive ground or storm water.

13.4     Mining Sequence and Production

Mining of the sand deposit at the Crane Operation commenced in 2018. Aside from a brief shutdown in late-2020 through early-

2021 due to poor market condition, the operation has been running continuously. Since 2020, the Crane Operation has mined

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7.8 million tons of raw sand. During 2020, production fell due to the COVID-19 pandemic to approximately 0.7 million ROM tons.

Production rebounded in 2021 and by 2022 rose to 3.9 million ROM tons. The LOM plan as illustrated in Figure 13.2, below, shows

forecasted production for the Crane Operation.

The proposed mining sequence is illustrated in Figure 13.3, on the following page. As shown, the proposed mining sequence

anticipates the remaining sand nearest to the processing facility will be mined out in a north-south fashion until 2027. Production will

continue in a north-south direction in 2028 until the eastern half of the deposit is depleted after 2037. At which point, mining will shift

to the western half of the deposit in 2038. Mining will be carried out in a north to south general direction until depletion of the deposit

in 2053. Any reclamation will occur concurrently with production as exhausted mining areas are returned to the agreed-upon final

design.

BOYD reviewed the LOM plans for U.S. Silica’s Crane Operation to determine whether the plans: (1) utilize generally accepted

engineering practices, and (2) align with historical and industry norms. Based on our assessment, it is BOYD’s opinion that the

forecasted production levels for the Crane Operation are reasonable, logical, and consistent with typical sand surface mining

practices in the Monahan Sandhill sands and historical results achieved by U.S. Silica.

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14-1

14.0    PROCESSING OPERATIONS

14.1    Overview

The Crane Operation’s processing facilities are located east of the active mining area on the same property as the mine.

Construction of the processing facilities and related infrastructure began in early 2018 and the first finished proppant sands were

produced in late 2018.

The production of finished proppant sand requires the processing of raw sand from the mine through two plants—the Wet

Processing Plant and the Dry Processing Plant. Figure 14.1, on page 14-3, presents a simplified process flow from the mine to the

product distribution.

The plan has a nominal capacity of 4.0 million tons of finished sand per year based on operating 24 hours a day and nearly 365

days per year.

BOYD is unaware of any reported interruptions, outages, shortages, or failures related to processing operations which have

materially affected the Crane Operation. Given the operation is well-established, we believe the risk of such events materially

affecting the estimates of proppant sand reserves presented herein is low.

14.1.1    Wet Processing Plant
The Wet Processing Plant receives its raw sand feed from a ROM stockpile supplied by the mine. The raw sand is reclaimed by a
front-end loader and passed through a static grizzly to remove any organics and oversize material. After passing the grizzly screen,

the sand is washed to remove any material larger than 1/4 in. The remaining material is mixed with water to create a slurry that is
passed through a series of desliming cyclones and attrition scrubbers to remove clay and undersized (very fine) particles. The
deslimed material is then processed through a series of hydrosizers, hydro-cyclones, and vacuum filters to remove excess water.
The remaining WIP material is stockpiled outside on a drain pad to further reduce moisture before it is recovered and enters the Dry

Processing Plant.

The oversized and organics waste material produced by the Wet Processing Plant is stored in a dry waste stockpile for use in future
reclamation activities. The clay and very fine “slimes”, or tailings, are pumped to settling ponds where the water is recovered for
future use. The water extracted by the hydrosizers, hydro-cyclones, vacuum filters, and drain pad is also recycled for use in the

processing operations.

14.1.2    Dry Processing Plant

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14-2

A front-end loader is used to recover the WIP material from the drain pad and feed it into one of two dryer feed hoppers in the Dry
Processing Plant. The dryer feed hoppers feed sand through one of three rotary dryers. After drying, the sand is sized and sorted

using screens into 40/70-mesh, 40/140-mesh, and “100-mesh” (50/140-mesh) products. Any remaining oversize material at this
point is screened off and deposited in the dry waste stockpile. The final products are stored in truck loadout silos for eventual
transfer to bulk trucks for shipment to customers.

JOHN T. BOYD COMPANY

14-3

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14.2 Production
The Crane Operation’s LOM plan forecasts increased production from the processing plant until the nominal production capacity is

reached. Recent annual production results and forecasted production over the expected life of the operation are provided in Figure
14.2.

14.3    Conclusion

Based on our review, it is BOYD’s opinion that the processing methods and existing equipment at the plant will be sufficient for the
forecasted production of finished proppant sand products.

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15.0    MINE INFRASTRUCTURE

15.1    Overview

All of the basic infrastructure required for the ongoing operations is in place at the Crane Operation. Figure 3.1 (page 3-2) illustrates

the general layout of the infrastructure at the Crane Operation.

The surface facilities currently located at the operation are well constructed and have the necessary capacity/capabilities to support

the Crane Operation’s near-term operating plans. Operational preference may lead to the upgrading of some existing facilities if the

operation expands in the future.

BOYD is unaware of any reported interruptions, outages, shortages, or failures related to infrastructure requirements which have

materially affected the Crane Operation. Given the operation is well-established, we believe the risk of such events materially

affecting the estimates of proppant sand reserves presented herein is low.

15.2    Transportation

The Crane Operation is serviced by several roads maintained by the local municipality, county, and state governments. These roads

are either paved or well-maintained graded roadways. Road access is available year-round.

There is not any rail infrastructure available at the Crane Operation. All products are shipped via bulk trucks. Transloading is

required to use existing rail networks and U.S. Silica has no immediate plans to transport their products from the Crane Operation

using rail.

15.3    Utilities

Electric power for the processing plant is supplied by TXU Retail Energy Company.

Natural gas used by the processing plant is currently supplied by West Texas Gas Marketing, Inc.

Water for industrial purposes is supplied by Kermit Pipeline, LLC. Kermit operates a water gathering and transport system to provide

water to mining, oil, and gas operators

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15-2

in west Texas. Potable water for consumption is delivered by truck in jugs and bottles. There are no plans for connecting to a water

utility network.

15.4 Tailings Disposal

The mining and processing of proppant sand at the Crane Operation creates a substantial amount of waste tailings. These tailings

are typically a mixture of clay, very fine sand, and other non-silica minerals. Tailings are typically disposed of in ponds (former

mining pits) where the solid materials settle to the bottom and water is recovered for reuse.

These tailings ponds are currently located directly to the north of the Crane Operation’s processing plant. As mining progresses

westward, depleted pits will become new tailing disposal sites. A freshwater pond is maintained on the property so water can be

stored after processing through the tailings ponds.

15.5 Other Structures

Several other buildings are located on the property, including:

• Office buildings that host engineering, financial, and administrative staff.
• Several support buildings for housing machinery and maintenance activities.
• A warehouse for material storage and product bagging.
• Several product loadouts.
• Various pump structures and outbuildings.

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16-1

16.0    MARKET STUDIES

16.1    Market Overview

The Permian Basin’s proppant sand market is driven by unconventional horizontal drilling in the oil and gas industry. In the late

1990s, rapid advances in horizontal drilling and hydraulic fracturing (fracking) in North America ushered in large-scale commercial

oil and gas production. This fracking technique has been increasingly successful and modified over time to extract oil and gas held

in dense layers of shale rocks, whose low permeability had previously prevented the flow of hydrocarbons.

Hydraulic fracturing uses a mixture of water, chemicals, and proppant (natural sand or man-made sand-like substances) to fracture

shale rock and release hydrocarbons such as oil, natural gas, and natural gas liquids. The proppant acts to keep the fractures open

(prop) while the pressurized fluids flow back up the well piping. Wells have become more productive with the addition of horizontal

drilling capabilities, longer lateral lengths, and multi-stage fracks.

To reduce costs, many oilfield services companies and E&P companies shifted from using only premium branded proppant sands,

which had higher delivered costs, to locally sourced and lower-priced “in-basin” proppant sands. The first in-basin proppant sand

deposits mined (late-2017) in the U.S. were located in the Permian Basin of Texas. Permian Basin E&P companies noted favorable

results from locally sourced proppant sands, and as such, nearly every other energy basin has experienced a period of exploration

to locate suitable local sources of proppant sands.

U.S. Silica operates in a highly competitive market that is characterized by a small number of large, national proppant sand

producers and a larger number of small, regional or local, privately-owned producers. Competition in the industry is based on: (1)

delivered price; (2) product consistency and quality; (3) supply capacity and reliability; and (4) customer service and technical

support. The Crane Operation’s substantial on-site product storage capacity and its strategic, in-basin location allows shipping

finished products to regional customers by truck. Since transportation costs are a significant portion of the total cost to customers of

proppant sands, development of the Crane, Texas plant as a regional frac sand facility in the Permian Basin allows U.S. Silica to

compete against proppant sand products being shipped from distant states like Wisconsin, Illinois, and Missouri.

16.2    Historical Sales

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U.S. Silica supplies a range of proppant sand products to major oilfield services

companies and E&P companies operating in the Permian Basin. The Crane Operation is one of U.S. Silica’s two proppant sand

operations in west Texas. Finished proppant sand products supplied by the Crane Operation primarily consist of non-API standard

40/140-mesh and “100-mesh” (50/140-mesh) sized sand, with lesser amounts of API standard 40/70-mesh sized sand.

Recent historical sales data provided by U.S. Silica for the Crane Operation are summarized in Table 16.1, below.

Proppant sand demand dropped in 2020, as compared to 2019, due to the COVID-19 pandemic. However, recovery began in the

fourth quarter of 2020 and continued throughout 2021 and 2022. In 2020, the average selling price (ASP) for the Crane Operation’s

finished proppant sand products was $22.06 per sold ton. In 2021, the ASP dropped to $18.91 per sold ton; however, the ASP rose

to $30.78 per sold ton in 2022.

According to sales information provided by U.S. Silica for the Crane Operation:

• Contract sales account for approximately 60% of total product sales.

•

The top-five customer by sales revenue account for approximately 65% of total sales. U.S. Silica has a range of minimum
purchase supply agreements with customers with initial terms spanning through 2034.

BOYD is not aware of any material contracts for the sale of proppant sand from the Crane Operation.

16.3    Market Outlook

Despite rises in production, the Permian Basin’s demand for in-basin proppant sand outstripped supply in 2022. Consequently,

prices for in-basin finished proppant sand products rose significantly during the year. Sustained growth in demand for in-basin

proppant sand products is expected. Although it operates in a highly competitive market,

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it is expected that the Crane Operation will experience increased demand for its products due, in part, to its low costs and

established customer base.

Having survived the challenging environment of 2019 and 2020, BOYD believes the Crane Operation should continue to prove

viable into the future notwithstanding a sustained and significant energy price collapse. Their low-cost mining and processing

operations, strategic in-basin location, and high-quality products help to create an advantage compared with other regional and

national proppant sand producers.

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17.0    PERMITTING AND COMPLIANCE

17.1    Permitting

Numerous permits are required by federal, state, and municipal law for mining, processing, and related activities at the Crane

Operation. U.S. Silica reports that necessary permits to support current and near-term operations are in place or pending approval.

New permits or permit revisions may be necessary from time to time to facilitate future operations. Given sufficient time and

planning, U.S. Silica should be able to secure new permits, as required, to maintain its planned operations within the context of

current regulations.

A description of the salient permitting requirements for the Crane Operation follows.

The Texas Commission on Environmental Quality (TCEQ) requires an Industrial Hazardous Waste (IHW) Solid Waste Registration

(#97544) which covers cleanup of hydraulic or lubricating oils from mobile equipment, general trash, and other hydrocarbons

contaminated materials.

A Phase I Environmental Site Assessment (ESA) was performed prior to construction of the Crane Operation. The assessment

included observations of oil and gas infrastructure including several gas and crude oil pipelines, one active oil well, several

abandoned and plugged oil and gas wells, historic oil and gas water ponds, and several active and abandoned water wells.

Evidence of past crude oil leaks from pipelines adjacent to the property are also present. No historical or environmentally sensitive

habitats were found during the assessment.

U.S. Silica maintains a Stormwater Pollution Prevention Plan (SWPPP) at the Crane Operation to address requirements of the

federal Oil Pollution Prevention Regulations (40 CFR Part 122). The SWPPP outlines the treatment measures and best

management practices used on site to maintain stormwater discharges within the permit limitations. Stormwater that leaves the site

is authorized and outlined in the Stormwater Multi-Sector General Permit (MSGP) by the TCEQ (TXR05DW69).

A Petroleum Storage Tank (PST) registration (#90261) is held by the third-party contractor in charge of mining operations for a

double walled fuel tank used to fuel mobile equipment on site.

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Air emissions resulting from the processing plant and associated equipment at the Crane Operation are authorized by the TCEQ Air

Permit Program Permit #150360. Provisions of the permit specify the authorized maximum operating capacity at the facility,

currently at 345 tph for each dryer. The permit also allows for certain visible emissions at specific opacity. Quarterly visible

emissions and fugitive emissions determinations are required, as well as ambient air monitoring at the request of the TCEQ.

U.S. Silica maintains an annual Aggregate Production Operation registration (APO002546) with the TCEQ for annual production

reporting.

Under current regulations, the State of Texas does not require reclamation or remediation of surface mined lands by aggregate

(including proppant sand) operations.

17.2    Compliance

U.S. Silica reports having an extensive environmental management and compliance process designed to follow or to exceed

industry standards.

In their 2021 corporate sustainability report, U.S. Silica reports:

•

Increasing the use of renewable energy sources.

• Enhancing water conservation and recycling efforts across our footprint, ensuring that drawing, using, and discharging fresh

water is done responsibly and in compliance with water management regulations and standards.

• Employing pollution prevention measures, such as increased operational efficiency and the reuse and recycling of materials,

to minimize the impact of our activities on the environment.

• Conducting annual evaluations of policies, procedures, and programs related to habitat conservation.

Specifically at the Crane Operation, the following practices have been implemented to enhance the sustainability of the site:

•

Install a vacuum pad to enhance recovery of water from stockpiled sand; reducing water consumption and energy needed to
dry the material.

• Conducting habitat surveys in 2018 and 2021 for the Dunes Sagebrush Lizard; a rare species found only in southeastern

New Mexico and western Texas.

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Mine safety is regulated by MSHA. MSHA inspects the facilities a minimum of twice yearly. U.S. Silica’s safety record compares

favorably with its regional peers.

Based on our review of information provided by U.S Silica and available public information, it is BOYD’s opinion that the Crane

Operation’s record of compliance with applicable mining, water quality, and environmental regulations is generally typical for that of

the industry. BOYD is not aware of any regulatory violation or compliance issue which would materially impact the proppant sand

reserve estimate.

17.3    Post-Mining Land Use and Reclamation

There are no formal state or federal reclamation plans or permits required for the Crane Operation. However, general requirements

of U.S. Silica’s operating permits and licenses include:

• Stabilization of disturbed areas to prevent exposure of significant materials to stormwater which could discharge off-site.

• Demolition of water wells and septic tanks.

• Disposal of hazardous wastes.

Mine site reclamation costs are funded from U.S. Silica’s Asset Retirement Obligations (ARO) account. Funding of the ARO account

is included in the Crane Operation’s capital and operating costs discussed in Chapter 18 and included in the economic analysis

presented in Chapter 19. ARO cost estimates are reviewed annually. As a matter of good mining practice, U.S. Silica seeks to

conduct progressive reclamation throughout the operation’s mining life to minimize risk and costs at closure.

17.4    Community Engagement

BOYD is unaware of any plans, negotiations, agreements with local individuals or groups or commitments to ensure local

procurement and hiring.

U.S. Silica’s corporate sustainability report outlines the components of its core community engagement initiatives. It's stated

priorities include increasing charitable contributions to organization that support the local community and actively seeking

opportunities for volunteering and community engagement.

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18.0    CAPITAL AND OPERATING COSTS

18.1    Historical Financial Performance

Table 18.1 summarizes the past three years of financial data for the Crane Operation. We remind the reader that the COVID-19

pandemic caused severe economic, market, and other disruptions which began to affect U.S. Silica’s proppant sand operations in

the second quarter of 2020. The Crane Operation temporarily shut down in 2020 and reopened in 2021.

The Crane Operation processed stockpiled "non-resource" sand in 2020 that was excavated from the processing plant construction

site. Consequently, the reported product sales tonnage for 2020 is higher than the stated tonnage mined.

Gross revenues include income from product sales and shipping.

Total cash costs of sales include operating costs (i.e., mining, ongoing reclamation, processing, product loadout, and other related

costs) in addition to selling, general, and administrative expenses.

Capital expenditures include maintenance (sustaining) expenses and discretionary spending on continuous improvement projects to

drive and maintain cost efficiencies.

Based on the financial data presented above:

• Average realization increased from $22.06 per ton sold in 2020 to $30.78 per ton sold in 2022.

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•

Total cash cost of sales decreased from $16.67 per ton sold in 2020 to $14.15 per ton sold in 2022.

• EBITDA margin increased marginally from 24.4% in 2020 to 54.0% in 2022.

• Capital expenditures totaled almost $3.8 million over the three years, averaging $0.54 per ton sold.

18.2    Estimated Costs

The production and unit cost estimates provided by U.S. Silica are based on actual past performance and their customary internal

budget review and approvals process. Operating volumes are well-defined and understood, as are mining and processing

productivities. As such, it is BOYD’s opinion that the production and financial projections are reasonable and are likely to be within

±20% accuracy level.

This section contains forward-looking information related to capital and operating cost estimates for the Crane Operation.

There are inherent known and unknown risks and uncertainties associated with all mining operations. These risks, uncertainties,

and other factors are not quantifiable, but include, but are not limited to, adverse general economic conditions, operating hazards,

inherent uncertainties in interpreting engineering and geologic data, fluctuations in commodity prices and prices for operational

services, government regulation and political risks, as well as other risks commonly associated with the mining industry.

18.2.1    Projected Capital Expenditures

The Crane Operation and related facilities are fully developed and should not require any near-term major capital investment to

maintain full commercial production. Historically, the timing and amount of capital expenditures has been largely discretionary and

within U.S. Silica’s control. Their budgetary allocations for sustaining and

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discretionary capital expenditures over the next three years is provided in Table 18.2, below.

18-3

BOYD considers the near-term detailed capital expenditure schedule as presented by U.S. Silica to be reasonable and
representative of the capital necessary to operate the Crane Operation.

After 2025, capital expenditures are projected to increase 3% annually per year from 2025’s expenditures until the end of

operation’s life. As the Crane Operation is in a steady state of production, the projected capital expenditures are considered
reasonable and expected.

18.2.2    Projected Operating Costs
Operating cost estimates were developed based on recent actual costs and considering specific operational activity levels and cost

drivers. The estimates consider current and expected labor headcount and salaries, major consumables and unit prices, power
costs, and equipment and maintenance costs. The total operating cost estimate includes all site costs related to mining, processing,
and general and administrative activities.

In the near-term, U.S. Silica expects their unit operating costs to stay relatively consistent (on an uninflated basis). As such, the

projected total cash cost of sales over the life of the mine is $14.15 per ton sold. As the operation is in a steady state, BOYD

considers the future operating cost estimates to be reasonable and appropriate.

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19.0    ECONOMIC ANALYSIS

19.1    Approach

The economic analysis presented in this chapter was made for the purposes of confirming the commercial viability of the Crane

Operation’s reported proppant sand reserves and not for the purposes of valuing U.S. Silica, the Crane Operation, or its assets. The

economic analysis contains forward-looking information related to the projected operating and financial performance of the Crane

Operation and therefore involves inherent known and unknown risks and uncertainties, some of which may be outside of U.S.

Silica’s control. U.S. Silica, as with all mining companies, actively evaluates, changes, and modifies business and operating plans in

response to various factors that may affect operational and/or financial results. Actual results, production levels, operating

expenses, sales realizations, and all other modifying factors could vary significantly from the assumptions and estimates provided in

this analysis. Risk is subjective, as such, BOYD recommends that each reader should evaluate the project based on their own

investment criteria.

The financial model used for the purposes of the economic analysis has been prepared in-house by U.S. Silica as part of their

annual budgeting process. The model forecasts future free cash flow from proppant sand production and sales over the life cycle of

the Crane Operation using the annual forecasts of production, sales revenues, and operating and capital costs discussed earlier in

this report. A DCF analysis, in which future free cash flows are discounted to present value, is used to derive an NPV for the

proppant sand reserves. Use of DCF-NPV analysis is a standard method within the mining industry to assess the economic value of

a project after allowing for the cost of capital invested.

The financial evaluation of the Crane Operation has been undertaken on a simplified after-tax basis and does not reflect U.S.

Silica’s corporate tax structure. NPV is calculated using an after-tax discount rate of 12.5% (NPV ). Cash flows were assumed to

12.5

occur in the middle of each year and are discounted to mid-year 2022. Cost estimates and other inputs to the cash flow model for

the project have been prepared using constant 2022 money terms, i.e., without provision for inflation. Internal rate of return and

project payback were not calculated, as there was no initial investment (sunk costs) considered in the financial model provided

herein.

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A suite of sensitivities was calculated to evaluate the effect of the main drivers of economic performance, including variations in

sales prices, operating costs, and capital costs.

BOYD has reviewed the financial model and its inputs in detail. It is our opinion that the financial model provides a reasonable and

accurate reflection of the Crane Operation’s expected economic performance based on the assumptions and information available

at the time of our review.

19.2    Assumptions and Limitations

Cash flow projections for the Crane Operation have been generated from the annual forecasts of production, sales revenues, and

operating and capital costs discussed earlier in this report. A summary of the key assumptions and limitations is provided below:

• Sales volumes of finished proppant sand are expected to increase 2% per annum.

• ROM production requirements are based on an expected processing yield of 82.5% (the historic average) and are also projected
to increase 2% per annum. Forecasted ROM production is at or below the capacity of the existing mining equipment and related
infrastructure.

•

Forecasted revenues are based on sales of various grades of finished proppant sand with a weighted-average sales price of
$23.92 per ton.

• Capital and operating costs are discussed in Chapter 18. Capital expenditures are derived from budgetary allocations for the

first three years of the forecast and escalated thereafter at 3% per annum. Unit operating costs are expected to remain relatively
constant over the life of the operation at $14.15 per sold ton.

•

Taxes are based on combined Federal and State Tax rates totaling 26%

• Buildup of net working capital is equal to 25% of positive cash (operating) margins.

• Depreciation and amortization expenses are estimated as the average of the proceeding three years.

• Asset recovery/salvage values were not included in the valuation.

19.3    Financial Model Results

Estimated LOM pre-tax and after-tax cash flows for proppant sand production from the Crane Operation are presented in Table

19.1, on the following page.

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Table 19.2, below, provides a summary of the estimated remaining life of mine financial results for the Crane Operation.

19-4

DCF-NPV on a pre-tax and after-tax basis, using discount rates of 10%, 12.5% (the base case), and 15%, were calculated utilizing

the projected cash flows. Table 19.3 summarizes the results of the pre-tax and after-tax DCF-NPV analyses:

As shown, the pre-tax DCF-NPV ranges from approximately $254.4 million to $362.4 million. The after-tax DCF-NPV ranges from

approximately $214.6 million to $305.2 million.

The economic analysis confirms that the Crane Operation generates positive pre- and after-tax financial results and a real NPV

12.5

of $252.5 million. As such, it is BOYD’s

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opinion that the Crane Operation’s proppant sand reserves have demonstrated economic viability.

19.4    Sensitivity Analysis

Table 19.4, below, shows the sensitivity of the project after-tax for a cash flow discounted at 12.5% (NPV ) to a variation over a

12.5

range of 20% above and below the base case in: (1) average selling prices and (2) operating costs.

As might be expected, the project is most sensitive to changes in product pricing and operating costs. The project is less sensitive

to capital costs. There is little to no impact varying the capital costs from 70% to 130% of the base case.

This analysis demonstrates the project value to be relatively robust, with positive NPVs reported across the range of values

assessed.

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20.0    ADJACENT PROPERTIES

There is no information used in this report that has been sourced from adjacent properties. BOYD is unaware of any mining or

exploration activities having occurred on the adjacent properties.

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21.0    OTHER RELEVANT DATA AND INFORMATION

BOYD is not aware of any additional information which would materially impact the proppant sand resource and reserve estimates

reported herein.

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22.0    INTERPRETATION AND CONCLUSIONS

22.1    Audit Findings

BOYD’s independent technical assessment was conducted in accordance with S-K 1300 and concludes:

• Sufficient data have been obtained through site exploration and sampling programs and mining operations to support the

geological interpretations of the sand deposit within the controlled property of the Crane Operation. The data are of sufficient
quantity and reliability to reasonably support the proppant sand resource and reserve estimates presented in this report.

• BOYD is of the opinion that our data verification efforts: (1) adequately confirm the reasonableness of the geologic

interpretations, resource estimation criteria, and economic assumptions; and (2) support the use of the data in proppant sand
resource/reserve estimation.

•

•

•

The 121.9 million saleable product tons of proppant sand reserves (as of December 31, 2022) identified on the property are
reasonably and appropriately supported by technical studies, which consider expected geologic conditions, planned mining and
processing operations, forecasted product revenues, and operating and capital cost estimates. As such, BOYD is of the opinion
that there are reasonable expectations that the stated proppant sand reserves for the Crane Operation are technically,
economically, and legally extractable as of December 31, 2022.

In addition to the reported reserves, U.S. Silica controls approximately 2.2 million in-place tons of measured and indicated
proppant sand resources and 16.4 million in-place tons of inferred proppant sand resources at the Crane Operation. It is
BOYD’s opinion that the stated proppant sand resources have been reported using economic and mining assumptions which
support the reasonable potential for eventual economic extraction.

There is no other relevant information material to the Crane Operation that is necessary to make this technical report summary
not misleading.

22.2    Significant Risks and Uncertainties

As a mining operation with an established operating history, the purpose of U.S. Silica’s periodic mine planning exercises is to: (1)

collect and analyze sufficient data to reduce or to eliminate risk in the technical components of the project, and (2) to refine

economic projections based on current data. There is a high degree of certainty for this project under the current and foreseeable

operating environment. A general assessment of risk is presented in the relevant sections of this report.

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23.0    RECOMMENDATIONS

Based on the scope of our assignment, BOYD has no recommendations regarding the Crane Operation. It is our understanding that

U.S. Silica continuously reviews and improves operating practices as a matter of course.

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24.0    REFERENCES

A list of supporting information is provided in Section 2.4. Additional references are cited as footnotes in the report as required.

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25.0    RELIANCE ON INFORMATION PROVIDED BY REGISTRANT

In the preparation of this report, BOYD has relied, exclusively and without independent verification, upon information furnished by

U.S. Silica as presented in Table 25.1, below.

BOYD exercised due care in reviewing the information provided by U.S. Silica within the scope of our expertise and experience

(which is in technical and financial mining issues) and concluded the data are reasonable and appropriate considering the status of

the subject properties and the purpose for which this report was prepared. We have no reason to believe that any material facts

have been withheld or misstated, or that further analysis may reveal additional material information. However, the accuracy of the

results and conclusions of this report are reliant on the accuracy of the information provided by U.S. Silica.

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