Data / Mines / Montana / Stone mines
Stone mines in Montana: 36 open mines and MSHA citations
MSHA lists 36 open stone mines in Montana, run by 23 operators and employing 344 people. Since January 1, 2022 its inspectors issued 378 citations and orders there with $84,555 in proposed penalties, and operators reported 62 injury or illness cases. The operators with the most open mines are Montana Rockworks Inc.; Block Mountain Slate & Stone Inc; Glacier Stone Supply LLC. Data from MSHA, November 6, 2026.
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- Open mines
- 36
- Operators
- 23
- Employees
- 344
- Intermittent
- 20
- Active
- 13
- Temporarily Idled
- 3
- Mines run by individuals, counted and not listed
- 4
- Citations and orders since January 1, 2022
- 378
- Significant and substantial
- 53 (14.0%)
- Closure orders
- 9
- High negligence or reckless
- 21
- Proposed penalties
- $84,555
- Amount paid so far
- $82,040
- Inspections
- 286
- Inspector hours on site
- 1,837
- Citations per inspection
- 1.32 (all mines 2.30)
- Accident reports
- 64
- Injury and illness cases
- 62
- Fatalities
- 0
- Latest MSHA record
- October 16, 2026
Operators with the most open mines in Montana
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 |
|---|---|---|---|---|---|
| Montana Rockworks Inc. | 4 | 21 | 24 | $3,912 | 9 |
| Block Mountain Slate & Stone Inc | 3 | 9 | 10 | $1,454 | 7 |
| Glacier Stone Supply LLC | 3 | 6 | 7 | $1,161 | 0 |
| Perma Stone Inc | 2 | 6 | 26 | $4,258 | 0 |
| Ironside Stone Works Inc | 2 | 5 | 15 | $2,325 | 0 |
| E S Stone & Structure | 2 | 22 | 11 | $2,583 | 5 |
| Montana Solid Rock Quarry, Inc | 2 | 10 | 7 | $1,041 | 0 |
| GCC Trident LLC | 1 | 82 | 96 | $32,472 | 12 |
| Graymont Western US Inc | 1 | 39 | 47 | $10,090 | 7 |
| Venture Stone LLC | 1 | 4 | 25 | $4,094 | 0 |
| Hollow Contracting Inc | 1 | 2 | 24 | $4,596 | 0 |
| Ash Grove Cement Company | 1 | 80 | 19 | $4,313 | 18 |
| Pipestone Quarry, LLC | 1 | 7 | 15 | $2,183 | 1 |
| Montana Limestone Company | 1 | 17 | 13 | $2,254 | 3 |
| D-Rockboyz LLC | 1 | 1 | 7 | $931 | 0 |
| Havre Sand & Gravel Inc | 1 | 4 | 7 | $931 | 0 |
| Huppert Brothers Construction Inc. | 1 | 5 | 4 | $2,157 | 0 |
| Gallatin County | 1 | 4 | 1 | $143 | 0 |
| Griffith Excavating Inc | 1 | 0 | 1 | $357 | 0 |
| Noble Excavating Inc | 1 | 2 | 1 | $133 | 0 |
| Montana Frontier SandStone LLC | 1 | 3 | 0 | $0 | 0 |
Operators with the most citations in Montana
Citations and orders issued since January 1, 2022 at their open mines here.
| Operator | Open mines | Employees | Citations since 2022 | Proposed penalties | Injury cases |
|---|---|---|---|---|---|
| GCC Trident LLC | 1 | 82 | 96 | $32,472 | 12 |
| Graymont Western US Inc | 1 | 39 | 47 | $10,090 | 7 |
| Perma Stone Inc | 2 | 6 | 26 | $4,258 | 0 |
| Venture Stone LLC | 1 | 4 | 25 | $4,094 | 0 |
| Montana Rockworks Inc. | 4 | 21 | 24 | $3,912 | 9 |
| Hollow Contracting Inc | 1 | 2 | 24 | $4,596 | 0 |
| Ash Grove Cement Company | 1 | 80 | 19 | $4,313 | 18 |
| Ironside Stone Works Inc | 2 | 5 | 15 | $2,325 | 0 |
| Pipestone Quarry, LLC | 1 | 7 | 15 | $2,183 | 1 |
| Montana Limestone Company | 1 | 17 | 13 | $2,254 | 3 |
| E S Stone & Structure | 2 | 22 | 11 | $2,583 | 5 |
| Block Mountain Slate & Stone Inc | 3 | 9 | 10 | $1,454 | 7 |
| Glacier Stone Supply LLC | 3 | 6 | 7 | $1,161 | 0 |
| Montana Solid Rock Quarry, Inc | 2 | 10 | 7 | $1,041 | 0 |
| D-Rockboyz LLC | 1 | 1 | 7 | $931 | 0 |
| Havre Sand & Gravel Inc | 1 | 4 | 7 | $931 | 0 |
| Huppert Brothers Construction Inc. | 1 | 5 | 4 | $2,157 | 0 |
| Gallatin County | 1 | 4 | 1 | $143 | 0 |
| Griffith Excavating Inc | 1 | 0 | 1 | $357 | 0 |
| Noble Excavating Inc | 1 | 2 | 1 | $133 | 0 |
| Montana Frontier SandStone LLC | 1 | 3 | 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 |
|---|---|---|---|---|---|
| Trident Plant & Quarry | GCC Trident LLC | Gallatin County, MT | Cement | 82 | 96 |
| Indian Creek Lime Plant & Quarry | Graymont Western US Inc | Broadwater County, MT | Lime | 39 | 47 |
| Ramage Pit 2 | Venture Stone LLC | Golden Valley County, MT | Dimension stone | 4 | 25 |
| Portable Crusher | Hollow Contracting Inc | Silver Bow County, MT | Crushed, broken stone | 2 | 24 |
| Montana City Plant | Ash Grove Cement Company | Jefferson County, MT | Cement | 80 | 19 |
| Mcgregor | Montana Rockworks Inc. | Flathead County, MT | Dimension stone | 8 | 18 |
| Camas Site #1 | Perma Stone Inc | Sanders County, MT | Dimension stone | 5 | 18 |
| Pipestone Quarry | Pipestone Quarry, LLC | Jefferson County, MT | Dimension basalt | 7 | 15 |
| Ironside Stone Works Quarry | Ironside Stone Works Inc | Lewis And Clark County, MT | Dimension slate | 3 | 15 |
| Warren Quarry | Montana Limestone Company | Carbon County, MT | Crushed, broken limestone | 17 | 13 |
| E S Stone and Structure Mobile 3 | E S Stone & Structure | Wheatland County, MT | Dimension stone | 19 | 10 |
| Dog Lake Quarry | Perma Stone Inc | Lake County, MT | Dimension stone | 1 | 8 |
| Havre Sand & Gravel, Inc | Havre Sand & Gravel Inc | Hill County, MT | Crushed, broken granite | 4 | 7 |
| D-Rockboyz Quarry | D-Rockboyz LLC | Carbon County, MT | Dimension stone | 1 | 7 |
| Montana Solid Rock Quarry #4 | Montana Solid Rock Quarry, Inc | Sanders County, MT | Dimension stone | 7 | 6 |
| Portable Crew #1 | Block Mountain Slate & Stone Inc | Sanders County, MT | Dimension stone | 2 | 6 |
| Clarks Fork Quarry | Huppert Brothers Construction Inc. | Yellowstone County, MT | Dimension stone | 5 | 4 |
| Castle Rock | Montana Rockworks Inc. | Flathead County, MT | Dimension slate | 2 | 4 |
| Portable Crew #3 | Block Mountain Slate & Stone Inc | Sanders County, MT | Dimension sandstone | 4 | 3 |
| Glacier Mobile 2 | Glacier Stone Supply LLC | Flathead County, MT | Dimension stone | 2 | 3 |
| Glacier Mobile 3 | Glacier Stone Supply LLC | Flathead County, MT | Dimension stone | 2 | 2 |
| Glacier Mobile 1 | Glacier Stone Supply LLC | Flathead County, MT | Dimension slate | 2 | 2 |
| Moose Mountain | Montana Rockworks Inc. | Flathead County, MT | Dimension sandstone | 9 | 1 |
| Logan Screen | Gallatin County | Gallatin County, MT | Dimension stone | 4 | 1 |
| Portable Crew #2 | Block Mountain Slate & Stone Inc | Sanders County, MT | Dimension stone | 3 | 1 |
| E S Stone and Structure Mobile 2 | E S Stone & Structure | Golden Valley County, MT | Dimension stone | 3 | 1 |
| Montana Solid Rock Quarry #3 | Montana Solid Rock Quarry, Inc | Sanders County, MT | Dimension sandstone | 3 | 1 |
| Montana Antique | Montana Rockworks Inc. | Lincoln County, MT | Dimension stone | 2 | 1 |
| Portable #2 | Noble Excavating Inc | Lincoln County, MT | Crushed, broken stone | 2 | 1 |
| Griffith Excavating, Inc. | Griffith Excavating Inc | Fallon County, MT | Dimension stone | 0 | 1 |
| Cowboy Cliff Quarry | Montana Frontier SandStone LLC | Golden Valley County, MT | Dimension stone | 3 | 0 |
| Madison Slate Quarry | Ironside Stone Works Inc | Fergus County, MT | Dimension limestone | 2 | 0 |
Main commodities
| Main commodity | Open mines | Share |
|---|---|---|
| Dimension stone | 20 | 55.6% |
| Crushed, broken stone | 3 | 8.3% |
| Dimension slate | 3 | 8.3% |
| Dimension sandstone | 3 | 8.3% |
| Cement | 2 | 5.6% |
| Lime | 1 | 2.8% |
| Dimension basalt | 1 | 2.8% |
| Crushed, broken limestone | 1 | 2.8% |
| Crushed, broken granite | 1 | 2.8% |
| Dimension limestone | 1 | 2.8% |
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 | 116 | 18 | $32,354 | 15 |
| 2023 | 64 | 10 | $12,366 | 13 |
| 2024 | 73 | 7 | $13,346 | 8 |
| 2025 | 84 | 13 | $18,372 | 15 |
| 2026 | 41 | 5 | $8,117 | 11 |
Standards cited most at stone mines in Montana
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 50.30 | Reporting of accidents, injuries and illnesses | 30 |
| 30 CFR 56.12028 | Surface metal and nonmetal mines | 25 |
| 30 CFR 56.20003 | Surface metal and nonmetal mines | 22 |
| 30 CFR 56.14100 | Surface metal and nonmetal mines | 21 |
| 30 CFR 56.4201 | Surface metal and nonmetal mines | 21 |
| 30 CFR 56.14107 | Surface metal and nonmetal mines | 13 |
| 30 CFR 56.14132 | Surface metal and nonmetal mines | 13 |
| 30 CFR 56.14112 | Surface metal and nonmetal mines | 12 |
| 30 CFR 56.17001 | Surface metal and nonmetal mines | 10 |
| 30 CFR 56.12002 | Surface metal and nonmetal mines | 10 |
| 30 CFR 56.13021 | Surface metal and nonmetal mines | 9 |
| 30 CFR 56.1000 | Surface metal and nonmetal mines | 9 |
| 30 CFR 56.9300 | Surface metal and nonmetal mines | 8 |
| 30 CFR 56.18002 | Surface metal and nonmetal mines | 7 |
| 30 CFR 56.11001 | Surface metal and nonmetal mines | 7 |
Injury and illness cases at stone mines in Montana
Accident reports by degree of injury, as the operator reported them to MSHA.
| Degree | Cases |
|---|---|
| Days away from work or restricted activity | 46 |
| No lost time, or an occupational illness | 16 |
What the accident reports at stone mines in Montana describe
Accident classification, as MSHA codes the circumstances that contributed most directly.
| Classification | Reports |
|---|---|
| Handling of materials | 22 |
| Handtools (nonpowered) | 13 |
| Slip or fall of person | 13 |
| Machinery | 10 |
| Powered haulage | 2 |
| Disorders (repeated trauma) | 1 |
| Fire | 1 |
| Striking or bumping | 1 |
| Stepping or kneeling on object | 1 |
Equipment named in accident reports at stone mines in Montana
| Equipment | Reports |
|---|---|
| Hand tools (not powered) | 13 |
| Dimension stone machinery | 7 |
| Ore haulage trucks - off highway trucks | 4 |
| Front-end loader | 2 |
| Packaging machine | 1 |
| Welding machine | 1 |
| Bulldozer | 1 |
| Trucks | 1 |
| Forklift | 1 |
| Hand tools (powered) | 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.