Data / Mines / California / Twin Mountain Rock Venture
Twin Mountain Rock Venture: 20 MSHA citations
Updated November 6, 2026. Source: US Department of Labor, Mine Safety and Health Administration (MSHA), Open Government Data Sets.
Twin Mountain Rock Venture is an active construction sand and gravel surface mine in Inyo County, California, operated by Twin Mountain Rock Venture with 6 employees on MSHA's record (mine ID 0403623). Since January 1, 2022 MSHA inspectors issued 20 citations and orders there with $2,958 in proposed penalties, and 0 accident reports were filed there, with no injury or illness cases.
The request: Watch Twin Mountain Rock Venture (MSHA mine ID 0403623) in Inyo County, California: each new citation and each accident report. $10 of work on sign-up, no card.
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- MSHA mine ID
- 0403623
- Status
- Active since November 21, 1979
- Main commodity
- Construction sand and gravel
- Mine type
- Surface
- County
- Inyo County, California
- Nearest town
- Little Lake
- Operator
- Twin Mountain Rock Venture
- Employees
- 6
- MSHA field office
- San Bernardino CA Field Office
- Citations and orders since January 1, 2022
- 20
- Significant and substantial
- 3 (15.0%)
- Closure orders
- 0
- High negligence or reckless
- 1
- Proposed penalties
- $2,958
- Amount paid so far
- $2,958
- Inspections
- 12
- Inspector hours on site
- 56
- Citations per inspection
- 1.67 (all mines 2.30)
- Accident reports
- 0
- Injury and illness cases
- 0
- Fatalities
- 0
- Latest MSHA record
- October 8, 2026
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 | 5 | 0 | $695 | 0 |
| 2023 | 3 | 2 | $477 | 0 |
| 2024 | 10 | 1 | $1,470 | 0 |
| 2025 | 1 | 0 | $151 | 0 |
| 2026 | 1 | 0 | $165 | 0 |
Standards cited most at Twin Mountain Rock Venture
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 46.3 | Training at sand, gravel and surface stone mines | 2 |
| 30 CFR 56.12032 | Surface metal and nonmetal mines | 2 |
| 30 CFR 56.12002 | Surface metal and nonmetal mines | 2 |
| 30 CFR 56.4102 | Surface metal and nonmetal mines | 2 |
| 30 CFR 56.12004 | Surface metal and nonmetal mines | 2 |
| 30 CFR 56.12018 | Surface metal and nonmetal mines | 2 |
| 30 CFR 56.14112 | Surface metal and nonmetal mines | 2 |
| 30 CFR 56.11002 | Surface metal and nonmetal mines | 1 |
| 30 CFR 56.12008 | Surface metal and nonmetal mines | 1 |
| 30 CFR 56.14100 | Surface metal and nonmetal mines | 1 |
| 30 CFR 56.14107 | Surface metal and nonmetal mines | 1 |
| 30 CFR 56.14207 | Surface metal and nonmetal mines | 1 |
| 30 CFR 47.31 | Hazard communication | 1 |
Other open mines in Inyo County, California
| Mine | Operator | County | Main commodity | Employees | Citations since 2022 |
|---|---|---|---|---|---|
| Beck Mine | U.S. Iron, LLC. | Inyo County, CA | Iron ore | 4 | 53 |
| Fish Springs Quarry | American Perlite Company | Inyo County, CA | Perlite | 2 | 41 |
| 7/11 Materials, Coyote Valley Aggregate | 7/11 Materials Inc | Inyo County, CA | Construction sand and gravel | 3 | 36 |
| Global Pumice Mine, Olancha | Global Pumice, LLC | Inyo County, CA | Construction sand and gravel | 4 | 33 |
| Makayla | Global Pumice, LLC | Inyo County, CA | Pumice | 4 | 29 |
| Panamint Valley Limestone Quarry | PVL Inc. | Inyo County, CA | Crushed, broken limestone | 2 | 25 |
| Fort Independence Quarry | Grinding Rock Aggregates | Inyo County, CA | Sand, industrial | 3 | 23 |
| Dolomite Mine | F W Aggregate Inc | Inyo County, CA | Crushed, broken marble | 5 | 10 |
| Owens Lake Mine | U S Borax Inc | Inyo County, CA | Trona | 5 | 2 |
| Kmi Zeolite Mine | Kmi Zeolite Inc | Inyo County, CA | Zeolites | 1 | 0 |
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.