Crushed and Broken Limestone Mining and Quarrying (United States)

A Histometrics investor primer · NAICS 2022 code 212312

NAICS (North American Industry Classification System) code 212312 covers U.S. establishments that quarry and crush limestone and related calcareous rock. This primer is for both public-market investors (listed producers, materials and infrastructure funds) and private investors (private/private-equity-owned operators, and owners of mineral and royalty rights). Figures are current as of mid-2026, with data vintages noted.

The one fact to remember. Crushed limestone is cheap, heavy rock. It costs so much to truck that it becomes uneconomic to move more than roughly 25–50 miles. That single physical fact defines the whole industry: markets are local, not national. A well-located quarry near a growing city can be a de facto local monopoly with real, durable pricing power — even though limestone itself is geologically abundant. So although this is a "commodity" business, its producers are local price-setters, not pure price-takers at the mercy of a national exchange price. That is the opposite of oil, copper, or gold, and it is the crux of the investment case. [1][2][17]

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1. Overview

Crushed limestone is the single largest slice of the U.S. construction aggregates business — the bulk rock (crushed stone plus sand and gravel) that forms the base of every road and the coarse fill in concrete and asphalt. It is the extraction node: dig it, blast it, crush it, screen it, sell it by the ton to buyers within a short haul.

Why an investor cares. The economics are unusual for an extractive industry. Because freight protects each quarry's local market, prices are sticky and have risen faster than inflation, reserves last decades rather than years, and demand grows with the built environment. Earnings still swing — but with volume (construction activity), not with a crashing product price. That gives aggregates a milder, more resilient profile than oil, gas, coal, or metals, which is why the leading producers trade at premium valuations. [2][9][10]

Ways in.

• Public markets: a small number of listed producers (most cleanly Vulcan Materials and Martin Marietta), plus diversified building-materials groups, niche royalty/land companies, and broad materials or infrastructure funds. There is no pure-play crushed-limestone ETF (exchange-traded fund). [9][10][29]
• Private markets: direct or private-equity (PE) ownership of the fragmented long tail of ~1,400 producers, and ownership of the mineral and royalty rights under a quarry (collecting a per-ton royalty as rock is extracted). [12][13][26][28]

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2. What it is, and what it excludes

NAICS 212312 covers establishments that (1) develop a limestone quarry site and mine or quarry crushed and broken limestone — plus related calcareous rock such as dolomite, cement rock, marl, travertine, and calcareous tufa — and (2) preparation plants that mechanically process (crush, grind, wash, screen) limestone. It sits in industry group 2123 (Nonmetallic Mineral Mining and Quarrying) inside sector 21 (Mining, Quarrying, and Oil and Gas Extraction). [1]

Limestone is calcium carbonate; dolomite adds magnesium. Most goes into construction aggregate, but limestone is also feedstock for cement and lime and is used as agricultural lime, flue-gas desulfurization (FGD) sorbent, and metallurgical flux — so the code is broader than just road rock. [1][2]

What 212312 excludes (the boundaries matter, because economics and environmental liabilities differ sharply across them):

Key mental model: federal business statistics for "212312" count quarries and grinding plants, not the cement kilns, asphalt plants, or concrete plants many aggregate companies also own. Company reports go the other way: Vulcan and Martin Marietta disclose a consolidated "Aggregates" segment spanning crushed stone and sand and gravel, so company segment data is broader than the 212312 code. [1][9][10]

Ownership mix. Highly fragmented at the tail, with a professionalized top tier: ~1,400 producers nationally, dominated in investability by a handful of large public companies but not, at the national level, controlled by them (see §3 and §8). Foreign-parented groups (Ireland, Germany, Switzerland/Amrize lineage, Mexico, Greece) own a meaningful share of U.S. tonnage; PE and family firms own most of the rest. [2][7][9]

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3. How big it is

Two federal yardsticks measure two different universes. Both are correct; keep them labeled.

3a. The business (U.S. Census Bureau — our ground truth for 212312)

Implied average pay is roughly $79,500 per employee — well above the private-sector average, reflecting skilled, capital-heavy work. CBP (County Business Patterns) is the annual employer-business series (counts, employment, payroll — no revenue); the Economic Census is the five-year revenue benchmark. Note that even the largest independents can qualify as "small" under the SBA (Small Business Administration) 750-employee threshold, so the vast majority of the 483 firms are technically small businesses. [4][5][6]

National concentration is low. The Economic Census puts the four largest firms at just 28.6% of industry revenue, the top 8 at 38.5%, the top 20 at 55.2%, and the top 50 at 72%, with a Herfindahl-Hirschman Index (HHI, a standard concentration gauge) of only 287 — far below the 1,500 threshold antitrust agencies treat as "unconcentrated." Nationally, this is a fragmented industry. It only looks concentrated locally (see §8). [4]

3b. The physical commodity (U.S. Geological Survey — the authoritative physical measure)

The USGS (U.S. Geological Survey) reports the crushed stone commodity across all rock types, so its figures are broader than 212312:

Source: USGS Mineral Commodity Summaries 2025/2026. [2][3]

In 2025, ~1.5 billion metric tons of crushed stone worth ~$27 billion came from ~1,400 companies operating ~3,500 quarries. Limestone and dolomite are ~70% of tonnage, implying roughly 1.05 billion metric tons of limestone/dolomite — an arithmetic estimate, not a separately reported USGS figure (and the 70% should not be applied to the dollar value, since prices vary by grade and location). Granite is ~14%, traprock ~6%. Net import reliance is ~1%: this is a domestic, freight-protected industry. [2][3]

Why the two counts differ (undercount note). Census counts 1,376 establishments / 25,735 employees in 212312; USGS counts ~3,500 quarries / ~71,200 employment. The gap is not an error — USGS counts crushed-stone quarries of every rock type, many limestone quarries are captive to cement/concrete operations classified elsewhere, and Census counts only establishments whose primary activity is 212312. Both are internally consistent measures of different populations. [2][4][5]

Reserves. USGS calls U.S. stone reserves "adequate," and resources "plentiful" — but flags that high-purity limestone is geographically limited and, more importantly, that the binding constraint is not geology but permitted rock close to demand. The scarce asset is a specification-quality, permitted quarry within economical haul distance of a growing market, not limestone in the abstract. [2][3]

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4. The investable universe

Because company "aggregates" segments include sand and gravel (and, for the diversified names, cement and foreign operations), the figures below describe investable companies, not clean shares of NAICS 212312. Every one of these is leveraged to construction volumes and local pricing, not to a fungible limestone price. [9][10][11]

Public producers (NYSE-listed unless noted)

Note: Summit Materials is no longer public — Quikrete completed its ~$11.5 billion take-private in February 2025. [12]

Royalty / land vehicles (niche)

Unlike precious metals (Franco-Nevada, Wheaton), there is no large pure-play limestone royalty/streaming company. The closest listed exposures are FRP Holdings (a real-estate company with a meaningful aggregate mining-royalty segment — ~16,648 royalty acres, ~$10.5M mining royalty/rent in the first nine months of 2025) and Natural Resource Partners (NRP) (a mineral-rights partnership where aggregates are only a small slice, dominated by coal). [26][27]

Funds

No U.S.-listed ETF is a pure aggregate play. The nearest are XLB (Materials Select Sector SPDR — held VMC/CRH/MLM at ~4.5–4.7% each in mid-2026, but construction materials were only ~14% of the fund, with chemicals over half) and infrastructure funds PAVE and IFRA (which also hold machinery, engineering, and steel). [29]

Private, family, and foreign owners

The private layer is large and active: Quikrete (private) became a top-tier owner overnight via Summit; Rogers Group calls itself the largest privately held U.S. aggregates producer (~13 states, ~86 quarries, ~3,500 employees); Luck Stone is a multigenerational family firm; Blue Water Industries is a private-capital consolidation platform; and Carmeuse (Belgian) represents foreign private ownership of specialty limestone. No federal dataset quantifies the split among family, PE, foreign, and public ownership — any precise percentage would be speculative. [12][13][14][15][16]

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5. How the money works

This is a commodity business by product but a local-pricing business by economics.

The freight-limited local model

Crushed stone is low-value and high-weight, so transport frequently runs 30–70% of the delivered cost, and the economics break down beyond ~25–50 miles of trucking (roughly $0.08–$0.14 per ton-mile). Vulcan reports that ~80% of its shipments move by truck only, ~15% by truck after first moving by rail or water to a distribution yard, and under 5% directly by rail or water. Within a quarry's haul radius, permitting barriers and scarce sites mean few substitutes — a structural local monopoly or tight oligopoly. The BLM (Bureau of Land Management) makes the same point: rock and gravel are bulky, low-price products with very high transport costs, so local supply dominates. [9][18][22]

The per-ton "cost curve"

There is no national break-even for limestone comparable to oil's lifting cost or gold's AISC (all-in sustaining cost, the metals cash-cost benchmark). The relevant framework is price, cash cost, and gross profit — per ton. Vulcan's 2025 disclosures are a useful large-company proxy:

Martin Marietta realized ~$23.30/ton with ~$8.45/ton GAAP gross profit. Both sit above the USGS ~$18.50/ton all-producer average, because the majors skew to higher-value urban markets and report freight-adjusted (delivered-equivalent) pricing. Cash gross margin is not free-cash-flow margin — it excludes depreciation, overhead, interest, tax, and acquisitions. [2][9][10]

The striking feature: pricing has run counter to volume. Vulcan's shipments fell from 234.6M tons (2023) to 226.8M (2025) while freight-adjusted price rose ~15.6% and gross profit per ton climbed — hard to reconcile with a pure price-taking model. This margin resilience is the core of the investment case. [9]

Reserves, depletion, and capital intensity

• Reserve life is long. Vulcan holds 16.6 billion tons of proven-and-probable reserves (~63% owned, ~37% leased) — on the order of 70+ years at current output; Martin Marietta's are similar or longer. Long lives mean low reserve-replacement urgency versus oil and gas, where reserves deplete in years. These are portfolio averages, not a promise for any single quarry. [9][10]
• Depletion is a non-cash tax allowance that shields cash flow: U.S. law allows 5% percentage depletion for limestone sold as aggregate, road material, riprap, or ballast, rising to 14% for certain specialty chemical/metallurgical uses. [24]
• Capital intensity is real but manageable: quarries, crushers, screens, and haul fleets are expensive and long-lived. Vulcan spent ~$622M of aggregate capex in 2025 (~$2.74/ton, ~12.5% of revenue), roughly matching depreciation and depletion. The "high fixed cost, long life, local pricing" combination produces high, stable free cash flow once a quarry is developed — which is what draws long-horizon and infrastructure capital. [9]

Why margins still swing — but less

Aggregates are cyclical in volume (tied to construction) but the price leg is far stickier than exchange-traded commodities. Input costs — diesel, labor, explosives, steel, tires — can compress margins, and lower volumes raise unit costs because fixed costs stay put. But because the product price itself does not crash the way Brent, WTI (West Texas Intermediate crude), or copper can, earnings troughs are shallower than in oil, gas, coal, or metals. [2][9][10]

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6. What drives demand

Limestone demand is almost entirely derived from construction. USGS puts 2025 crushed-stone end uses at ~72% construction aggregate (mostly roads), 17% cement, 6% lime, 1% agriculture, 4% other. [2]

1. Public infrastructure — the swing factor. Roads, highways, and bridges are the largest single end-market, and federal funding is pivotal (see §7). Public work is steadier than private construction. [2][9]
2. Private non-residential — warehouses, factories, and increasingly data centers and energy/manufacturing megaprojects, which USGS flags as a 2026 demand support. [2]
3. Residential — interest-rate-sensitive; soft housing weighed on 2024–2025 volumes. [2]
4. Cement and lime — a slice of limestone feeds kilns, tying it to the cement cycle. [2]
5. Reshoring and electrification — chip fabs, battery/EV plants, and grid build-out are aggregate-intensive and largely independent of the housing cycle. [2]
6. Specialty and agricultural (aglime, FGD sorbent, metallurgical flux) — small, non-cyclical ballast that can earn premiums but needs specific chemistry. [2]

Long-run demand grows with population, urbanization, and the built-environment stock; short-run it tracks interest rates, weather, and the federal highway-funding cycle. [2]

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7. Regulation

Unlike federal-land hardrock or energy minerals, most limestone is quarried on private or state land, so the General Mining Law of 1872 and BLM leasing are largely irrelevant here. On the federal land that does apply, common stone is a saleable mineral material under the Materials Act of 1947 (sold at fair market value), not a locatable claim. The binding constraints are local and environmental: [22]

• Zoning and land-use permitting — the #1 barrier and the moat. Local zoning and conditional-use permits are the biggest constraint on new supply; USGS repeatedly warns that zoning and competing land uses are pushing quarries away from cities, creating regional shortages and "higher-than-average price increases" in urban areas. What blocks new entrants also protects incumbents' pricing. [2][9]
• MSHA (Mine Safety and Health Administration). Every quarry is federally regulated; surface mines get at least two inspections a year (training under Part 46). Aggregates are relatively safe as extraction goes — BLS (Bureau of Labor Statistics) recorded 3 fatal injuries in NAICS 212312 in 2024, with a total recordable case rate of 1.9 per 100 workers. MSHA's 2024 respirable crystalline-silica rule set a permissible exposure limit (PEL) of 50 µg/m³, though its metal/nonmetal compliance date was delayed indefinitely after a judicial stay — so dust-control capital remains prudent, but the exact deadline is unsettled. [19][20][21]
• EPA (Environmental Protection Agency). Clean Air Act New Source Performance Standards (40 CFR Part 60 Subpart OOO) govern particulate/dust from crushers and conveyors; Clean Water Act NPDES (National Pollutant Discharge Elimination System) permits and Section 404 (dredge-and-fill) cover quarry dewatering, stormwater, and wetlands; blasting is regulated for vibration and air-overpressure. [23]
• State permitting, reclamation, and taxes. States require mining/reclamation permits and financial assurance; several levy per-ton or ad-valorem severance/extraction taxes, modest relative to oil-and-gas regimes. [23]
• ESG / emissions. A limestone quarry's direct emissions are relatively low (diesel, electricity, blasting, dust). The carbon-intensive step is the cement/lime kiln downstream — so decarbonization pressure lands on the cement-bound ~17% of limestone, not the aggregate-bound share. [23]

Net: regulation here is a moat as much as a cost — every year it gets harder to permit a new quarry near a growing city, entrenching the value of existing reserves. [2][9]

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8. Competitive dynamics and consolidation

Fragmented nationally, concentrated locally. The apparent contradiction between "483 firms, HHI 287" (§3) and "local monopoly" (§5) is resolved by freight. Vulcan itself estimates ~5,000 companies run ~11,000 U.S. aggregate facilities, with the ten largest at only ~35% of national output and Vulcan itself ~10%. There is no national duopoly — Vulcan and Martin Marietta are a duopoly of listed pure-play large-caps, not of production. But a given town may have only two economically deliverable quarries. That is why the FTC (Federal Trade Commission) analyzes deals market-by-market: in CRH's acquisition of Ash Grove it treated crushed limestone in Johnson County, Kansas as its own market and required three quarry divestitures. [4][9][17]

Consolidation is relentless, and creates value by buying permitted reserves below replacement cost, combining adjacent positions, spreading overhead, and integrating asphalt/ready-mix. Recent deals: Quikrete–Summit (~$11.5B take-private, 2025); Martin Marietta's asset exchange with Quikrete and ~$6B of 2024 aggregates M&A; ongoing bolt-ons by CRH, Heidelberg, and family-owned Rogers Group. The risk is overpaying for reserve tons that cannot be profitably delivered — cheap rock without permits, access, quality, or nearby demand is expensive. Barriers to entry are high and rising: reserves near demand are scarce, permitting takes years, and incumbents hold the best sites. [9][10][12][13]

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9. Risks

1. Construction/volume cyclicality — the central risk. Volumes fall with recessions, high mortgage rates, and lapses in highway funding. For aggregates, "commodity-price risk" is really local price–volume–cost-spread risk, not exposure to one national exchange price — and the volume leg moves more than the price leg. [2][9]
2. Cost inflation. Diesel, labor, explosives, steel, and freight can compress margins; the model depends on pushing price faster than cost (achieved recently, not guaranteed). [9]
3. Federal funding cliff. The IIJA (Infrastructure Investment and Jobs Act, 2021) provides ~$351B of highway-specific funding and runs through fiscal 2026. Because funds already obligated keep flowing (DOT reported ~$232B obligated and ~$154B spent of ~$351B as of late 2025), a sunset would not halt work immediately — but the next surface-transportation reauthorization is a live medium-term overhang. (One USGS caution: early-2025 highway spending ran soft year-on-year — a single-source flag worth watching.) [2][25]
4. Permitting and regulatory delay. The same zoning that protects incumbents also constrains their ability to open or expand quarries. [2][9]
5. Depletion / stranded-location risk. The danger is not running out of limestone nationally, but exhausting a well-located urban quarry and being forced to haul from farther away — a margin risk, not a solvency risk, given multi-decade reserve lives. [9]
6. Energy-transition / stranded-asset risk — LOW for the aggregate share. Unlike coal or oil, construction rock faces little demand destruction from decarbonization; grid, EV, and renewables build-outs are aggregate-intensive. The exception is the cement-bound ~17% of limestone, exposed to cement's process-CO₂ pressure. [2][23]
7. Import risk — negligible. Net import reliance is ~1%; freight economics make imports irrelevant outside a few coastal metros. [2]

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10. How to invest, and outlook

Public routes

• Producer equities give leverage to local price increases, volume recovery, fixed-cost absorption, reserve appreciation, and accretive M&A — not to a fungible limestone price. Vulcan (VMC) and Martin Marietta (MLM) are the two liquid pure-play large-caps; VMC's market cap was ~$39B in mid-2026. CRH, Amrize, Knife River, Arcosa, Eagle Materials, and Titan America offer broader building-materials exposure. [9][10][30]
• No boom-bust dividend cycle. Because the product price does not crash, capital returns are steady and growing rather than feast-or-famine. These are compounders, not high-yielders — VMC yields ~0.7%, MLM ~0.5%; in 2025 each paid ~$200–260M in dividends and bought back ~$440–450M of stock, funding roughly sustainable dividends while buybacks and M&A absorb the cyclical surplus. Both trade at premium EV/EBITDA (enterprise value to EBITDA) multiples versus most extractive industries, precisely because of local pricing power and long reserve lives. [9][10][30]
• Royalty/land and funds are niche: FRP Holdings and Natural Resource Partners for aggregate-royalty exposure; XLB / PAVE / IFRA for diluted, diversified exposure. There is no pure-play limestone ETF or streaming company. [26][27][29]

Private routes

• Direct or PE ownership of the fragmented ~1,400-producer tail earns the same local-monopoly cash flows the majors do, often at lower entry multiples — the standard playbook is to buy an anchor quarry in a growth market, professionalize pricing and safety, add nearby reserves and distribution, and sell a regional platform to a strategic consolidator. Downsides are capital intensity, site concentration, permitting risk, environmental liability, and illiquidity. [12][13][15]
• Mineral and royalty (land) ownership — leasing reserves to an operator for the greater of a per-ton royalty or a percentage of gross (typically with minimum annual rents; observed rates range widely, roughly $0.20–$5.00/ton by state) — is a low-operational-risk, inflation-linked, very-long-duration income stream. But it is illiquid, appraisal-driven, dependent on compatible surface access, and has no securitized secondary market. [26][27][28]

What to watch: per-ton price and cash gross profit (the real value drivers), shipment volumes, reserve life and location quality, the M&A pipeline, and above all the post-IIJA highway reauthorization. [2][9]

Outlook

Base case (constructive). The structural story is intact: freight-protected local pricing, long reserve lives, permitting barriers that entrench incumbents, and tailwinds from infrastructure, reshoring, and data centers. USGS expects the price-supporting forces to persist into 2026, and Vulcan's own 2026 guidance calls for shipments up 1–3% and price up 4–6% (management guidance, not an independent forecast). The realistic risks are cyclical (volume) and political (funding) — not structural (demand destruction), the opposite risk profile from coal or oil. [2][9]

For a general investor, crushed limestone is best understood as a toll road on the built environment: cyclical in traffic, but with a durable, locally-protected toll. The correct unit of analysis is never "the U.S. limestone market" in the abstract — it is each quarry, its permits and reserve life, its logistics, and the competitive structure inside its actual delivery radius. [2][9][10]

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Sources

1. U.S. Census Bureau — 2022 NAICS Manual: NAICS 212312 definition and adjacent codes (212311/212313/212319/212321/213115/327310/327410/327320), 2022. https://www.census.gov/naics/
2. U.S. Geological Survey — Mineral Commodity Summaries 2026: Stone (Crushed), 2026 (production, value, end-use, reserves, price outlook, IIJA). https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-stone-crushed.pdf
3. U.S. Geological Survey — Mineral Commodity Summaries 2025: Stone (Crushed), 2025 (2020–2024 series). https://pubs.usgs.gov/periodicals/mcs2025/mcs2025-stone-crushed.pdf
4. U.S. Census Bureau — 2022 Economic Census, NAICS 212312: revenue $10.585B; 483 firms; concentration ratios CR4 28.6% / CR8 38.5% / CR20 55.2% / CR50 72%; HHI 287.1. https://data.census.gov/table/ECNBASIC2022.EC2200BASIC
5. U.S. Census Bureau — 2023 County Business Patterns, NAICS 212312: 1,376 establishments; 25,735 employees; $475.5M Q1 payroll; $2.045B annual payroll. https://www.census.gov/programs-surveys/cbp.html
6. U.S. Small Business Administration — Table of Small Business Size Standards / 13 CFR 121.201: NAICS 212312 = 750 employees (2023). https://www.sba.gov/document/support-table-size-standards
7. USGS via Pit & Quarry / Concrete Products — Top U.S. crushed-stone producers rankings, 2024. https://www.pitandquarry.com/vulcan-tops-usgss-2024-crushed-stone-producers-list/
8. National Stone, Sand & Gravel Association (NSSGA) — Industry economic data / media guide. https://www.nssga.org/
9. Vulcan Materials Company — 2025 Form 10-K (SEC EDGAR): 226.8M tons; $21.98/t price; $10.65/t cash cost; $11.33/t cash gross profit; $8.66/t GAAP gross profit; 16.6B tons reserves; $622.1M capex; $259.8M dividends; $438.4M buybacks. https://www.sec.gov/Archives/edgar/data/1396009/000162828026009546/vmc-20251231.htm
10. Martin Marietta Materials — 2025 Form 10-K and Annual Report: 198.5M tons; $23.30/t price; $8.45/t gross profit; ~16.0B tons reserves; ~$197M dividends; ~$450M buybacks. https://www.sec.gov/Archives/edgar/data/916076/000119312526059193/mlm-20251231.htm
11. CRH plc — 2025 Form 10-K, 2026. https://www.sec.gov/Archives/edgar/data/849395/000162828026009043/crh-20251231.htm
12. Summit Materials / Quikrete — Completion of merger, February 10, 2025 (~$11.5B EV, $52.50/share; Summit ceased NYSE trading). https://www.sec.gov/Archives/edgar/data/1621563/000095010325001807/dp224739_ex9901.htm
13. Rogers Group — Company and operating locations (largest privately held U.S. aggregates producer; ~13 states, ~86 quarries, ~3,500 employees), 2026. https://rogersgroupincint.com/
14. Luck Stone — Our Company (family-owned crushed-stone producer), 2026. https://www.luckstone.com/
15. Blue Water Advisors — Portfolio: Construction Aggregates (private-capital consolidation platform), 2026. https://bwalp.com/portfolio/
16. Carmeuse — About Us, North America (privately owned Belgian lime/limestone producer), 2026. https://www.carmeuse.com/na-en/about-us
17. Federal Trade Commission — CRH/Ash Grove divestiture and competitive analysis (Johnson County, Kansas local limestone market; three-quarry divestiture), 2018. https://www.ftc.gov/system/files/documents/cases/1710230_crh_plc_analysis.pdf
18. Aggregate freight economics — transport ≈ 30–70% of delivered cost; ~25–50-mile haul limit; ~$0.08–$0.14/ton-mile. Silvi Group; The Geography of Transport Systems. https://www.silvi.com/stone-aggregate-delivery-costs/
19. Mine Safety and Health Administration — Federal Mine Safety and Health Act; Part 46/48 training (surface mines inspected ≥2×/yr). https://arlweb.msha.gov/MSHAINFO/FactSheets/MSHAFCT1.HTM
20. U.S. Department of Labor / MSHA — Respirable Crystalline Silica Final Rule (50 µg/m³ PEL) and 2026 judicial-stay notification, 2024–2026. https://www.dol.gov/newsroom/releases/msha/msha20240416
21. U.S. Bureau of Labor Statistics — Fatal Occupational Injuries by Industry, 2024 (3 fatalities, NAICS 212312) and 2024 nonfatal injury/illness rates (TRC 1.9 per 100). https://www.bls.gov/iif/fatal-injuries-tables/fatal-occupational-injuries-table-a-1-2024.htm
22. Bureau of Land Management — Saleable Mineral Materials and Materials Act of 1947 classification, 2026. https://www.blm.gov/programs/energy-and-minerals/mining-and-materials/saleable-minerals
23. U.S. Environmental Protection Agency — Nonmetallic Mineral Processing NSPS (40 CFR Part 60 Subpart OOO); NPDES / Sector J; Clean Water Act §404, 2025. https://www.epa.gov/stationary-sources-air-pollution/nonmetallic-mineral-processing-new-source-performance-standards
24. U.S. Code — 26 U.S.C. §613, Percentage Depletion (5% construction limestone; 14% specialty). https://uscode.house.gov/view.xhtml?req=(title:26%20section:613%20edition:prelim)
25. Federal Highway Administration / U.S. DOT — IIJA highway funding (~$351B highway-specific through FY2026); IIJA financial summary as of Nov 30, 2025 (~$232B obligated, ~$154B outlaid). https://www.transportation.gov/
26. FRP Holdings — Form 10-Q, period ended September 30, 2025 (~16,648 royalty acres; ~$10.5M mining royalty/rent, 9 months). https://www.sec.gov/Archives/edgar/data/844059/000084405925000064/frph-20250930.htm
27. Natural Resource Partners L.P. — 2025 Form 10-K (mineral-rights partnership; aggregates a small share). https://www.sec.gov/Archives/edgar/data/1171486/000143774926006147/nrp20251231_10k.htm
28. Rock Associates — Observed sand, gravel, and quarry royalty rates (~$0.20–$5.00/ton by state). https://www.rockassociates.com/post/sand-gravel-and-quarry-royalty-rates
29. State Street Global Advisors — Materials Select Sector SPDR (XLB) holdings, July 2026; Global X U.S. Infrastructure Development ETF (PAVE); iShares U.S. Infrastructure ETF (IFRA). https://www.ssga.com/us/en/individual/etfs/state-street-materials-select-sector-spdr-etf-xlb
30. Vulcan Materials valuation snapshot — market cap ~$39B (mid-2026); VMC ~0.7% / MLM ~0.5% dividend yield. AAII; Yahoo Finance. https://finance.yahoo.com/quote/VMC/

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Evidence note. Core business statistics (revenue, firms, establishments, employment, payroll, concentration, HHI) are drawn from the U.S. Census Bureau's 2022 Economic Census and 2023 County Business Patterns for NAICS 212312 (our ingested ground truth). Physical production, value, price, and reserves are from USGS Mineral Commodity Summaries. Company figures are from 2025 SEC Form 10-K filings. Where a figure is an arithmetic estimate (e.g., ~1.05 billion metric tons of limestone/dolomite from the 70% share) or a single-source caution (e.g., soft early-2025 highway spending), it is labeled as such. Forward-looking statements in §10 are analytical judgments, not reported facts.