GRANITE CONSTRUCTION INC

Quarry Properties

We own or lease quarry properties that contain mineral resources that we extract and process into construction materials.

As defined by the SEC, mineral resources are 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.

As defined by the SEC, mineral reserves are an estimate of tonnage and grade or quality of indicated and measured mineral resources that, in the opinion of a qualified person, as defined by the SEC, 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.

Our mineral resources and reserves are based on estimates made by qualified persons who are employees of the Company and are based primarily on geological evidence, sampling and testing and appropriate modifying factors. Amounts presented in the tables below are based on various assumptions to determine estimated economically mineable tons including site specific prices for sand and gravel and hard rock between $5 - $40 per ton. The price per ton estimates use a saleable product (i.e., materials that are ready for sale) as a point of reference and are escalated over time by the Producer’s Price Index for Construction Sand, Gravel and Crushed Stone (product 1321). Pricing for aggregates tend to remain similar for long periods of time; therefore, we use current pricing to estimate prices and we reassess at least annually to verify there have not been material changes. Changes to the estimates and assumptions from those currently anticipated could have a material impact on the mineral resource and mineral reserve estimates.

As of December 31, 2024, we had open pit quarry properties available for the extraction of sand, gravel and hard rock. Our Materials segment uses these quarry properties to extract and process sand, gravel and hard rock into construction material for internal use in our construction projects and for sale to third parties. As of December 31, 2024, we had all the permits necessary to mine and process sand, gravel and hard rock at our active quarry properties. As of December 31, 2024, no individual mining operation was considered material to our business or financial condition. Annual production of aggregates for all mining properties was 18.7 million tons, 17.5 million tons, and 16.3 million tons during the years ended December 31, 2024, 2023 and 2022, respectively. The following map shows the approximate locations of our permitted quarry properties as of December 31, 2024:

California and Utah are the only states/provinces that individually comprise more than 10% of our total mining operations. The following tables present information about our quarry properties as of December 31, 2024 (tons in millions):

(1)Owned properties are properties we own or in which we have, or it is probable that we will have, a direct or indirect economic interest.

(2)Leases are defined as properties where we operate, or it is probable we will operate, under a lease or other legal agreement that grants us ownership or similar rights that authorize us, as principal, to sell or otherwise dispose of the mineral and includes properties that we sublease and from which we receive royalties, which are both considered immaterial. Our leases have terms which range from month-to-month to 50 years with most including an option to renew.

The life cycle of mining sand, gravel and hard rock begins with exploration and continues through development and production. After a sand, gravel and hard rock deposit has been identified through exploration, the mine is developed before production begins. The following table presents the number of properties in each respective stage as of December 31, 2024 for all mining properties:

Mineral Resources

The table below presents information on measured, indicated and inferred mineral resources. Estimates of measured mineral resources are based on conclusive geological evidence, sampling and testing and may be converted to a proven mineral reserve or to a probable mineral reserve. Estimates of indicated mineral resources are based on adequate geological evidence, sampling and testing and may only be converted to a probable mineral reserve when sufficient evidence is identified including consideration of modifying factors such as mining, processing, economic and environmental factors. Modifying factors are the factors that a qualified person must apply to indicated and measured mineral resources and then evaluate to establish the economic viability of mineral reserves. Estimates of inferred mineral resources have significant geological uncertainty based on limited geological evidence, sampling and testing and therefore may not be converted to a mineral reserve.

As of December 31, 2024, our qualified persons estimated our measured, indicated and inferred resources to be approximately 494.9 million tons. As of December 31, 2024, California and Utah were the only individual states/provinces that comprised more than 10% of our total mining operations. The Wine Group, Aerojet North White Rock and Coalinga Section 30 were the only mines that comprised 10% or more of our combined measured and indicated mineral resources for sand and gravel and the Euer Ranch and Bamberton Quarry were the only mines that comprised 10% or more of our combined measured and indicated mineral resources for hard rock. The following table presents information about our mineral resources at December 31, 2024 (tons in millions):

(1)The grade of product produced is contingent on market needs. Sites typically sell base products that range from low to high grades including fill materials, base aggregates, hot mix aggregates and concrete aggregates.

Mineral Reserves

Mineral reserves are divided into proven and probable mineral reserves. Proven mineral reserves are the economically mineable part of a measured mineral resource and can only result from the conversion of a measured mineral resource. Proven mineral resources are determined by a qualified person through the testing of samples obtained from closely spaced subsurface drilling and/or exposed pit faces, and are sufficiently understood so that quantity, quality and engineering conditions are known with sufficient accuracy to be mined without the need for any further subsurface work. Probable mineral reserves are the economically mineable part of an indicated, and in some cases, a measured mineral resource. Probable mineral reserves are determined through the testing of samples obtained from subsurface drilling, but the sample points are too widely spaced to allow detailed prediction of quantity, quality and engineering conditions. Additional subsurface work may be needed prior to mining the reserve.

The modifying factors applied in the conversion of measured and indicated mineral resources to proven and probable mineral reserves during the year ended December 31, 2024 included various relevant technical and economic factors, including site infrastructure, mine design and planning, processing plant and environmental compliance and permitting. The basis of determining the modifying factors was a combination of historical experience mining aggregates and observation.

As of December 31, 2024, our qualified persons estimated our proven and probable reserves to be approximately 1.1 billion tons. Waste factors for proven and probable reserves range up to 44% depending on the deposit type, market characteristics and extraction feasibility. As of December 31, 2024, California and Utah were the only individual states/provinces that comprised more than 10% of our total mining operations, Coalinga, Solari and Grantsville were the only mines that comprised 10% or more of our mineral reserves for sand and gravel and Handley Quarry, Lockwood Mustang and Bamberton Quarry were the only mines that comprised 10% or more of our mineral reserves for hard rock. The following table presents information about mineral reserves at December 31, 2024 (tons in millions):

(1)The grade of product produced is contingent on market needs. Sites typically sell base products that range from low to high grades including fill materials, base aggregates, hot mix aggregates and concrete aggregates.

Internal controls

Mining operations include risk in estimation of mineral reserves and mineral resources that could be impacted by unforeseen geologic circumstances, changes in regulation or changes in sales and customers. The risk that these estimates would be unreasonable based on the known information is mitigated by the following internal controls that we use in our exploration and mineral resource and mineral reserve estimation efforts:

•quality control and quality assurance programs including management identifying the qualified person(s) with the appropriate background and qualifications to prepare the information used for disclosure purposes;

•verification of analytical procedures including management reviewing the mineral resource and reserve report information for completeness, accuracy and appropriateness, such as categorization, inclusion of technical, economic and operational factors, discounted cash flow analysis inputs, assumptions and calculations, and mining, metallurgical, legal, environmental compliance and governmental modifying factors as well as comparison of estimates to historic production and prior period estimates; and

•review of disclosures to ensure compliance with requirements.

Plant Properties

We operate plants at our quarry sites to process aggregates into construction materials. Some of our sites may have more than one crushing, concrete or asphalt processing plant. The following table presents the number of plants we owned and leased as of the respective dates:

(1) Three of our asphalt concrete plants were operated under lease agreements for the years ended December 31, 2024 and 2023.

These plants are used by both of our reportable segments.