Data / Mines / Wyoming / Stone mines
Stone mines in Wyoming: 15 open mines and MSHA citations
MSHA lists 15 open stone mines in Wyoming, run by 12 operators and employing 297 people. Since January 1, 2022 its inspectors issued 488 citations and orders there with $333,135 in proposed penalties, and operators reported 57 injury or illness cases, 1 of them fatal. The operators with the most open mines are Martin Marietta Materials, Inc.; Colorado Lien Company; JTL Group, Inc.. Data from MSHA, November 6, 2026.
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- Open mines
- 15
- Operators
- 12
- Employees
- 297
- Active
- 7
- Intermittent
- 6
- Temporarily Idled
- 2
- Mines run by individuals, counted and not listed
- 1
- Citations and orders since January 1, 2022
- 488
- Significant and substantial
- 79 (16.2%)
- Closure orders
- 9
- High negligence or reckless
- 27
- Proposed penalties
- $333,135
- Amount paid so far
- $265,091
- Inspections
- 160
- Inspector hours on site
- 2,276
- Citations per inspection
- 3.05 (all mines 2.30)
- Accident reports
- 60
- Injury and illness cases
- 57
- Fatalities
- 1
- Latest MSHA record
- November 4, 2026
Operators with the most open mines in Wyoming
Ranked by open mines, then by citations. Sole proprietors and individuals are not listed.
| Operator | Open mines | Employees | Citations since 2022 | Proposed penalties | Injury cases |
|---|---|---|---|---|---|
| Martin Marietta Materials, Inc. | 2 | 52 | 52 | $18,031 | 5 |
| Colorado Lien Company | 2 | 58 | 37 | $7,453 | 9 |
| JTL Group, Inc. | 2 | 2 | 0 | $0 | 0 |
| Mountain Cement Company LLC | 1 | 127 | 217 | $207,824 | 31 |
| Tongue River Stone Inc | 1 | 3 | 32 | $8,379 | 0 |
| Simon Contractors | 1 | 7 | 30 | $5,022 | 5 |
| High Country Construction, Inc. | 1 | 2 | 7 | $1,031 | 1 |
| Searle Brothers Construction Company | 1 | 2 | 7 | $1,055 | 0 |
| Loudwire Minerals, LLC | 1 | 2 | 6 | $984 | 0 |
| Croell, Inc. | 1 | 4 | 2 | $302 | 1 |
| FireSteel Well Service Inc. | 1 | 2 | 0 | $0 | 0 |
Operators with the most citations in Wyoming
Citations and orders issued since January 1, 2022 at their open mines here.
| Operator | Open mines | Employees | Citations since 2022 | Proposed penalties | Injury cases |
|---|---|---|---|---|---|
| Mountain Cement Company LLC | 1 | 127 | 217 | $207,824 | 31 |
| Martin Marietta Materials, Inc. | 2 | 52 | 52 | $18,031 | 5 |
| Colorado Lien Company | 2 | 58 | 37 | $7,453 | 9 |
| Tongue River Stone Inc | 1 | 3 | 32 | $8,379 | 0 |
| Simon Contractors | 1 | 7 | 30 | $5,022 | 5 |
| High Country Construction, Inc. | 1 | 2 | 7 | $1,031 | 1 |
| Searle Brothers Construction Company | 1 | 2 | 7 | $1,055 | 0 |
| Loudwire Minerals, LLC | 1 | 2 | 6 | $984 | 0 |
| Croell, Inc. | 1 | 4 | 2 | $302 | 1 |
| JTL Group, Inc. | 2 | 2 | 0 | $0 | 0 |
| FireSteel Well Service Inc. | 1 | 2 | 0 | $0 | 0 |
Mines with the most citations
Open mines, ranked by citations and orders since January 1, 2022.
| Mine | Operator | County | Main commodity | Employees | Citations since 2022 |
|---|---|---|---|---|---|
| Mountain Cement Company | Mountain Cement Company LLC | Albany County, WY | Cement | 127 | 217 |
| Granite Canyon Quarry | Martin Marietta Materials, Inc. | Laramie County, WY | Crushed, broken granite | 42 | 34 |
| Tongue River Stone Inc | Tongue River Stone Inc | Sheridan County, WY | Crushed, broken stone | 3 | 32 |
| Crusher #1 | Simon Contractors | Laramie County, WY | Crushed, broken stone | 7 | 30 |
| Wyoming Lime Products | Colorado Lien Company | Park County, WY | Lime | 15 | 26 |
| Guernsey Quarry | Martin Marietta Materials, Inc. | Platte County, WY | Crushed, broken limestone | 10 | 18 |
| Jonathon Quarry | Colorado Lien Company | Albany County, WY | Crushed, broken limestone | 43 | 11 |
| Leucite Mine #11 | Searle Brothers Construction Company | Sweetwater County, WY | Crushed, broken stone | 2 | 7 |
| Riprap Plant | High Country Construction, Inc. | Fremont County, WY | Crushed, broken stone | 2 | 7 |
| Sherman Hills Quarry | Loudwire Minerals, LLC | Albany County, WY | Dimension granite | 2 | 6 |
| West Crusher #4 | Croell, Inc. | Converse County, WY | Crushed, broken limestone | 4 | 2 |
| Crusher #6 | JTL Group, Inc. | Natrona County, WY | Crushed, broken limestone | 2 | 0 |
| Pickrel #2 | FireSteel Well Service Inc. | Campbell County, WY | Crushed, broken stone | 2 | 0 |
| Crusher #2 | JTL Group, Inc. | Natrona County, WY | Crushed, broken stone | 0 | 0 |
Main commodities
| Main commodity | Open mines | Share |
|---|---|---|
| Crushed, broken stone | 7 | 46.7% |
| Crushed, broken limestone | 4 | 26.7% |
| Cement | 1 | 6.7% |
| Crushed, broken granite | 1 | 6.7% |
| Lime | 1 | 6.7% |
| Dimension granite | 1 | 6.7% |
Citations and injury cases by year
Calendar years since 2022; 2026 runs to the date of the MSHA files.
| Year | Citations and orders | Significant and substantial | Proposed penalties | Injury and illness cases |
|---|---|---|---|---|
| 2022 | 112 | 17 | $58,335 | 7 |
| 2023 | 87 | 10 | $127,045 | 9 |
| 2024 | 88 | 11 | $42,890 | 6 |
| 2025 | 102 | 20 | $58,259 | 14 |
| 2026 | 99 | 21 | $46,606 | 21 |
Standards cited most at stone mines in Wyoming
Sections of Title 30 of the Code of Federal Regulations named on the citations, with the part each belongs to.
| Standard | What the part covers | Citations |
|---|---|---|
| 30 CFR 56.20003 | Surface metal and nonmetal mines | 52 |
| 30 CFR 56.12004 | Surface metal and nonmetal mines | 32 |
| 30 CFR 56.12028 | Surface metal and nonmetal mines | 30 |
| 30 CFR 56.14107 | Surface metal and nonmetal mines | 27 |
| 30 CFR 56.12032 | Surface metal and nonmetal mines | 26 |
| 30 CFR 56.14100 | Surface metal and nonmetal mines | 25 |
| 30 CFR 56.14112 | Surface metal and nonmetal mines | 23 |
| 30 CFR 56.12030 | Surface metal and nonmetal mines | 18 |
| 30 CFR 56.12018 | Surface metal and nonmetal mines | 16 |
| 30 CFR 56.18002 | Surface metal and nonmetal mines | 16 |
| 30 CFR 56.4201 | Surface metal and nonmetal mines | 14 |
| 30 CFR 56.14205 | Surface metal and nonmetal mines | 13 |
| 30 CFR 56.12008 | Surface metal and nonmetal mines | 10 |
| 30 CFR 56.11001 | Surface metal and nonmetal mines | 8 |
| 30 CFR 46.9 | Training at sand, gravel and surface stone mines | 7 |
Injury and illness cases at stone mines in Wyoming
Accident reports by degree of injury, as the operator reported them to MSHA.
| Degree | Cases |
|---|---|
| Fatality | 1 |
| Days away from work or restricted activity | 16 |
| No lost time, or an occupational illness | 40 |
What the accident reports at stone mines in Wyoming describe
Accident classification, as MSHA codes the circumstances that contributed most directly.
| Classification | Reports |
|---|---|
| Handling of materials | 23 |
| Machinery | 10 |
| Slip or fall of person | 7 |
| Other | 5 |
| Handtools (nonpowered) | 4 |
| Powered haulage | 3 |
| Nonpowered haulage | 2 |
| Striking or bumping | 1 |
| Stepping or kneeling on object | 1 |
| Exploding vessels under pressure | 1 |
Equipment named in accident reports at stone mines in Wyoming
| Equipment | Reports |
|---|---|
| Hand tools (powered) | 6 |
| Hand tools (not powered) | 4 |
| Crane | 2 |
| Machine | 2 |
| Front-end loader | 2 |
| Ore haulage trucks - off highway trucks | 1 |
| Hoist | 1 |
| Welding machine | 1 |
| Tugger | 1 |
| Forklift | 1 |
Updated November 6, 2026. Read from US Department of Labor, Mine Safety and Health Administration (MSHA), Open Government Data Sets. US government work, public domain. Counts come from the MSHA files published on November 6, 2026. An open mine is one MSHA lists as Active, Intermittent, New Mine, Temporarily Idled or NonProducing; 13,673 were open that day. Citations, penalties, inspections and accident reports run from January 1, 2022. A citation is an inspector's allegation and an operator can contest it; the penalty is the amount MSHA first proposed, before any contest or settlement. An operator is the legal entity MSHA assesses, and a parent company is its controller. Mines run by sole proprietors or by individuals are counted in every total and are not named. This page uses MSHA data and is not endorsed or certified by MSHA. Free to reuse with credit to SpecStream under CC BY 4.0. Spot a wrong value? Write to [email protected] with the link to this page.