Data / Mines / California / Kern County
Mines in Kern County, California: 20 open mines
MSHA lists 20 open mines in Kern County, California, run by 19 operators and employing 1,428 people. Since January 1, 2022 its inspectors issued 1,530 citations and orders there with $1,575,268 in proposed penalties, and operators reported 137 injury or illness cases, 2 of them fatal. The operators with the most open mines are CalPortland Company; U S Borax Inc; National Cement Company of California Inc. Data from MSHA, November 6, 2026.
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- Open mines
- 20
- Operators
- 19
- Employees
- 1,428
- Active
- 18
- Intermittent
- 2
- Citations and orders since January 1, 2022
- 1,530
- Significant and substantial
- 381 (24.9%)
- Closure orders
- 33
- High negligence or reckless
- 127
- Proposed penalties
- $1,575,268
- Amount paid so far
- $1,361,934
- Inspections
- 368
- Inspector hours on site
- 6,039
- Citations per inspection
- 4.16 (all mines 2.30)
- Accident reports
- 154
- Injury and illness cases
- 137
- Fatalities
- 2
- Latest MSHA record
- October 29, 2026
Operators with the most open mines in Kern County, California
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 |
|---|---|---|---|---|---|
| CalPortland Company | 2 | 134 | 279 | $185,951 | 24 |
| U S Borax Inc | 1 | 624 | 364 | $642,375 | 40 |
| National Cement Company of California Inc | 1 | 112 | 334 | $320,617 | 31 |
| Unacem North America | 1 | 101 | 173 | $57,863 | 12 |
| Golden Queen Mining Company | 1 | 179 | 106 | $121,040 | 20 |
| Taft Production Company | 1 | 56 | 48 | $72,299 | 4 |
| MRC Rock & Sand, LLC. | 1 | 5 | 37 | $29,569 | 0 |
| Lost Hills Mining LLC | 1 | 21 | 35 | $90,880 | 3 |
| Sydney Peak Stone, Inc. | 1 | 48 | 27 | $23,282 | 0 |
| Big Iron DG Mine LLC | 1 | 1 | 23 | $4,199 | 0 |
| CalMat Co | 1 | 25 | 21 | $5,820 | 0 |
| Nestle Purina PetCare Company | 1 | 86 | 21 | $8,392 | 1 |
| 7/11 Materials Inc | 1 | 4 | 19 | $4,562 | 0 |
| Griffith Company | 1 | 15 | 14 | $3,594 | 0 |
| Edison Sand & Gravel, Inc. | 1 | 2 | 10 | $1,349 | 0 |
| Robertson's Ready Mix Ltd | 1 | 2 | 10 | $2,090 | 0 |
| Kern Brothers Trucking Inc | 1 | 1 | 4 | $596 | 0 |
| Granite Construction Company | 1 | 4 | 3 | $496 | 0 |
| Holliday Rock Company Inc | 1 | 8 | 2 | $294 | 2 |
Operators with the most citations in Kern County, California
Citations and orders issued since January 1, 2022 at their open mines here.
| Operator | Open mines | Employees | Citations since 2022 | Proposed penalties | Injury cases |
|---|---|---|---|---|---|
| U S Borax Inc | 1 | 624 | 364 | $642,375 | 40 |
| National Cement Company of California Inc | 1 | 112 | 334 | $320,617 | 31 |
| CalPortland Company | 2 | 134 | 279 | $185,951 | 24 |
| Unacem North America | 1 | 101 | 173 | $57,863 | 12 |
| Golden Queen Mining Company | 1 | 179 | 106 | $121,040 | 20 |
| Taft Production Company | 1 | 56 | 48 | $72,299 | 4 |
| MRC Rock & Sand, LLC. | 1 | 5 | 37 | $29,569 | 0 |
| Lost Hills Mining LLC | 1 | 21 | 35 | $90,880 | 3 |
| Sydney Peak Stone, Inc. | 1 | 48 | 27 | $23,282 | 0 |
| Big Iron DG Mine LLC | 1 | 1 | 23 | $4,199 | 0 |
| CalMat Co | 1 | 25 | 21 | $5,820 | 0 |
| Nestle Purina PetCare Company | 1 | 86 | 21 | $8,392 | 1 |
| 7/11 Materials Inc | 1 | 4 | 19 | $4,562 | 0 |
| Griffith Company | 1 | 15 | 14 | $3,594 | 0 |
| Edison Sand & Gravel, Inc. | 1 | 2 | 10 | $1,349 | 0 |
| Robertson's Ready Mix Ltd | 1 | 2 | 10 | $2,090 | 0 |
| Kern Brothers Trucking Inc | 1 | 1 | 4 | $596 | 0 |
| Granite Construction Company | 1 | 4 | 3 | $496 | 0 |
| Holliday Rock Company Inc | 1 | 8 | 2 | $294 | 2 |
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 |
|---|---|---|---|---|---|
| Boron Operations | U S Borax Inc | Kern County, CA | Boron minerals | 624 | 364 |
| Lebec Cement Plant | National Cement Company of California Inc | Kern County, CA | Cement | 112 | 334 |
| Mojave Plant & Quarry | CalPortland Company | Kern County, CA | Cement | 133 | 276 |
| Tehachapi Cement, LLC. | Unacem North America | Kern County, CA | Cement | 101 | 173 |
| Soledad Mountain Project | Golden Queen Mining Company | Kern County, CA | Gold ore | 179 | 106 |
| Taft Production Company & Mines | Taft Production Company | Kern County, CA | Common clays | 56 | 48 |
| Mojave Rock Mine | MRC Rock & Sand, LLC. | Kern County, CA | Construction sand and gravel | 5 | 37 |
| Lost Hills Mining | Lost Hills Mining LLC | Kern County, CA | Gypsum | 21 | 35 |
| Sydney Peak Stone | Sydney Peak Stone, Inc. | Kern County, CA | Dimension stone | 48 | 27 |
| Big Iron DG Mine | Big Iron DG Mine LLC | Kern County, CA | Crushed, broken granite | 1 | 23 |
| Maricopa Plant | Nestle Purina PetCare Company | Kern County, CA | Crushed, broken stone | 86 | 21 |
| San Emidio Plant | CalMat Co | Kern County, CA | Construction sand and gravel | 25 | 21 |
| Canebrake Pit | 7/11 Materials Inc | Kern County, CA | Construction sand and gravel | 4 | 19 |
| Edmonston Rock Plant | Griffith Company | Kern County, CA | Construction sand and gravel | 15 | 14 |
| Edison Sand Pit | Edison Sand & Gravel, Inc. | Kern County, CA | Construction sand and gravel | 2 | 10 |
| Ridgecrest Rock Plant | Robertson's Ready Mix Ltd | Kern County, CA | Construction sand and gravel | 2 | 10 |
| Portable #1 | Kern Brothers Trucking Inc | Kern County, CA | Construction sand and gravel | 1 | 4 |
| Solari Sand and Gravel | Granite Construction Company | Kern County, CA | Construction sand and gravel | 4 | 3 |
| Gem Hill Mine Site | CalPortland Company | Kern County, CA | Cement | 1 | 3 |
| Mojave Pit | Holliday Rock Company Inc | Kern County, CA | Construction sand and gravel | 8 | 2 |
Main commodities
| Main commodity | Open mines | Share |
|---|---|---|
| Construction sand and gravel | 9 | 45% |
| Cement | 4 | 20% |
| Boron minerals | 1 | 5% |
| Gypsum | 1 | 5% |
| Crushed, broken stone | 1 | 5% |
| Common clays | 1 | 5% |
| Dimension stone | 1 | 5% |
| Gold ore | 1 | 5% |
| Crushed, broken granite | 1 | 5% |
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 | 253 | 65 | $212,127 | 30 |
| 2023 | 500 | 136 | $654,712 | 36 |
| 2024 | 323 | 82 | $336,317 | 22 |
| 2025 | 231 | 44 | $257,204 | 30 |
| 2026 | 223 | 54 | $114,908 | 19 |
Standards cited most at mines in Kern County, California
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 56.14112 | Surface metal and nonmetal mines | 174 |
| 30 CFR 56.20003 | Surface metal and nonmetal mines | 145 |
| 30 CFR 56.14107 | Surface metal and nonmetal mines | 115 |
| 30 CFR 56.12032 | Surface metal and nonmetal mines | 101 |
| 30 CFR 56.12004 | Surface metal and nonmetal mines | 89 |
| 30 CFR 56.14100 | Surface metal and nonmetal mines | 73 |
| 30 CFR 56.18002 | Surface metal and nonmetal mines | 52 |
| 30 CFR 56.16001 | Surface metal and nonmetal mines | 52 |
| 30 CFR 56.12008 | Surface metal and nonmetal mines | 36 |
| 30 CFR 56.4201 | Surface metal and nonmetal mines | 32 |
| 30 CFR 56.12018 | Surface metal and nonmetal mines | 28 |
| 30 CFR 56.11001 | Surface metal and nonmetal mines | 27 |
| 30 CFR 56.12028 | Surface metal and nonmetal mines | 24 |
| 30 CFR 56.17001 | Surface metal and nonmetal mines | 23 |
| 30 CFR 56.12002 | Surface metal and nonmetal mines | 23 |
Injury and illness cases at mines in Kern County, California
Accident reports by degree of injury, as the operator reported them to MSHA.
| Degree | Cases |
|---|---|
| Fatality | 2 |
| Permanent disability | 2 |
| Days away from work or restricted activity | 84 |
| No lost time, or an occupational illness | 49 |
What the accident reports at mines in Kern County, California describe
Accident classification, as MSHA codes the circumstances that contributed most directly.
| Classification | Reports |
|---|---|
| Handling of materials | 41 |
| Slip or fall of person | 30 |
| Handtools (nonpowered) | 18 |
| Powered haulage | 14 |
| Other | 13 |
| Machinery | 12 |
| Disorders (repeated trauma) | 6 |
| Fire | 3 |
| Ignition or explosion of gas or dust | 3 |
| Electrical | 3 |
Equipment named in accident reports at mines in Kern County, California
| Equipment | Reports |
|---|---|
| Hand tools (not powered) | 19 |
| Ore haulage trucks - off highway trucks | 10 |
| Milling machinery | 6 |
| Front-end loader | 6 |
| Hand tools (powered) | 5 |
| Elevator | 3 |
| Conveyor | 2 |
| Trucks | 2 |
| Carriage-mounted drills | 2 |
| Forklift | 2 |
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.