Data / Mines / California / Gem Hill Mine Site
Gem Hill Mine Site: 3 MSHA citations
Updated November 6, 2026. Source: US Department of Labor, Mine Safety and Health Administration (MSHA), Open Government Data Sets.
Gem Hill Mine Site is an intermittent cement surface mine in Kern County, California, operated by CalPortland Company with 1 employee on MSHA's record (mine ID 0405976). Since January 1, 2022 MSHA inspectors issued 3 citations and orders there with $441 in proposed penalties, and 0 accident reports were filed there, with no injury or illness cases.
The request: Watch Gem Hill Mine Site (MSHA mine ID 0405976) in Kern County, California: each new citation and each accident report. $10 of work on sign-up, no card.
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- MSHA mine ID
- 0405976
- Status
- Intermittent since April 20, 2026
- Main commodity
- Cement
- Mine type
- Surface
- County
- Kern County, California
- Nearest town
- Mojave
- Operator
- CalPortland Company
- Parent company
- Taiheiyo Cement Corp
- Employees
- 1
- MSHA field office
- San Bernardino CA Field Office
- Citations and orders since January 1, 2022
- 3
- Significant and substantial
- 0 (0.0%)
- Closure orders
- 0
- High negligence or reckless
- 0
- Proposed penalties
- $441
- Amount paid so far
- $441
- Inspections
- 3
- Inspector hours on site
- 16
- Citations per inspection
- 1.00 (all mines 2.30)
- Accident reports
- 0
- Injury and illness cases
- 0
- Fatalities
- 0
- Latest MSHA record
- June 10, 2026
- Citations issued to contractors here
- 4 ($1,008 proposed)
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 |
|---|---|---|---|---|
| 2024 | 3 | 0 | $441 | 0 |
Standards cited most at Gem Hill Mine Site
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 56.1000 | Surface metal and nonmetal mines | 1 |
| 30 CFR 56.14100 | Surface metal and nonmetal mines | 1 |
| 30 CFR 56.14132 | Surface metal and nonmetal mines | 1 |
Other open mines in Kern County, California
| 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 |
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.