Data / Mines / California / Riverside County
Mines in Riverside County, California: 36 open mines
MSHA lists 36 open mines in Riverside County, California, run by 28 operators and employing 587 people. Since January 1, 2022 its inspectors issued 684 citations and orders there with $284,463 in proposed penalties, and operators reported 83 injury or illness cases. The operators with the most open mines are Robertson's Ready Mix Ltd; Chandler Aggregates Inc; West Coast Aggregate Supply. Data from MSHA, November 6, 2026.
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- Open mines
- 36
- Operators
- 28
- Employees
- 587
- Active
- 34
- Intermittent
- 2
- Citations and orders since January 1, 2022
- 684
- Significant and substantial
- 164 (24.0%)
- Closure orders
- 15
- High negligence or reckless
- 93
- Proposed penalties
- $284,463
- Amount paid so far
- $237,184
- Inspections
- 475
- Inspector hours on site
- 3,045
- Citations per inspection
- 1.44 (all mines 2.30)
- Accident reports
- 84
- Injury and illness cases
- 83
- Fatalities
- 0
- Latest MSHA record
- November 4, 2026
Operators with the most open mines in Riverside County, California
Ranked by open mines, then by citations. Sole proprietors and individuals are not listed.
Operators with the most citations in Riverside County, California
Citations and orders issued since January 1, 2022 at their open mines here.
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 |
|---|---|---|---|---|---|
| 3M Corona Plant | 3M Company | Riverside County, CA | Crushed, broken stone | 85 | 66 |
| 3M | Fst Sand & Gravel Inc | Riverside County, CA | Construction sand and gravel | 93 | 47 |
| Coachella Valley Aggregate | Coachella Valley Aggregates Inc | Riverside County, CA | Construction sand and gravel | 11 | 39 |
| Nichols Road Pit | Chandler Aggregates Inc | Riverside County, CA | Construction sand and gravel | 23 | 35 |
| North Fontana | Earth Tek Engineering Corp. | Riverside County, CA | Construction sand and gravel | 6 | 35 |
| HJ Hove | Hi-Grade Materials | Riverside County, CA | Construction sand and gravel | 19 | 34 |
| Chandler Aggregates, Gilman Springs | Chandler Aggregates Inc | Riverside County, CA | Dimension limestone | 20 | 32 |
| Pacific Aggregates Pits | Pacific Aggregates Inc | Riverside County, CA | Construction sand and gravel | 30 | 31 |
| Maitri Sand and Gravel | Hanson Aggregates LLC | Riverside County, CA | Construction sand and gravel | 15 | 30 |
| Thousand Palms Pit | Coronet Concrete Products Inc | Riverside County, CA | Construction sand and gravel | 6 | 28 |
| Plant #5 | Onyx Materials | Riverside County, CA | Construction sand and gravel | 3 | 28 |
| West Coast Aggregate Supply Inc | West Coast Aggregate Supply | Riverside County, CA | Construction sand and gravel | 11 | 26 |
| Maitri Canyon Plant | Foster Sand & Gravel | Riverside County, CA | Construction sand and gravel | 19 | 24 |
| West Coast Aggregate Supply Inc | West Coast Aggregate Supply | Riverside County, CA | Construction sand and gravel | 6 | 24 |
| All American Aggregates | All American Aggregates | Riverside County, CA | Construction sand and gravel | 55 | 22 |
| Crawford's Mine | Crawford Associates | Riverside County, CA | Construction sand and gravel | 3 | 21 |
| Dillon Road Pit | Superior Ready Mix Concrete L P | Riverside County, CA | Construction sand and gravel | 3 | 20 |
| Mayhew Plant | Mamr LLC DBA Maitri Road Recycling | Riverside County, CA | Construction sand and gravel | 5 | 19 |
| Juniper Flats | Robertson's Ready Mix Ltd | Riverside County, CA | Construction sand and gravel | 6 | 16 |
| Corona | Robertson's Ready Mix Ltd | Riverside County, CA | Construction sand and gravel | 27 | 13 |
| The Standard Mine | Double D Mining LLC | Riverside County, CA | Gypsum | 10 | 13 |
| Dillon Plant | Coronet Concrete Products Inc | Riverside County, CA | Construction sand and gravel | 2 | 12 |
| 968ab Power Screen | Riverside County Transportation Dept | Riverside County, CA | Construction sand and gravel | 1 | 11 |
| Banning | Robertson's Ready Mix Ltd | Riverside County, CA | Construction sand and gravel | 14 | 10 |
| Eagle Mountain Mine | Aggregate & Mineral Resource Group LLC | Riverside County, CA | Construction sand and gravel | 10 | 9 |
| Cabazon | Robertson's Ready Mix Ltd | Riverside County, CA | Construction sand and gravel | 28 | 7 |
| Portable Plant #1 | Quality Aggregates Inc. | Riverside County, CA | Construction sand and gravel | 3 | 7 |
| Eagle Valley | Pacific States Transportation | Riverside County, CA | Sand, industrial | 1 | 7 |
| Corona Plant | CalMat Co | Riverside County, CA | Construction sand and gravel | 33 | 3 |
| Painted Hills Quarry | Painted Hills Mining Company | Riverside County, CA | Construction sand and gravel | 6 | 3 |
| Pacific Clay Pits | Pacific Clay Products Inc | Riverside County, CA | Common clays | 4 | 3 |
| S-5 Red | Upland Rock | Riverside County, CA | Construction sand and gravel | 2 | 3 |
| 966ab Mccloskey | Riverside County Transportation Dept | Riverside County, CA | Construction sand and gravel | 3 | 2 |
| Portable Plant | Transamerican Soil Service | Riverside County, CA | Sand, common | 1 | 2 |
| Eagle Valley Aggregates | Hanson Aggregates LLC | Riverside County, CA | Construction sand and gravel | 19 | 1 |
| Riverside Operation | Riverside Milling Company, LLC | Riverside County, CA | Ground silica | 4 | 1 |
Main commodities
| Main commodity | Open mines | Share |
|---|---|---|
| Construction sand and gravel | 29 | 80.6% |
| Crushed, broken stone | 1 | 2.8% |
| Common clays | 1 | 2.8% |
| Ground silica | 1 | 2.8% |
| Dimension limestone | 1 | 2.8% |
| Sand, industrial | 1 | 2.8% |
| Gypsum | 1 | 2.8% |
| Sand, common | 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 | 126 | 32 | $41,296 | 16 |
| 2023 | 121 | 33 | $80,106 | 15 |
| 2024 | 159 | 37 | $66,225 | 20 |
| 2025 | 130 | 26 | $47,349 | 15 |
| 2026 | 148 | 36 | $49,487 | 17 |
Standards cited most at mines in Riverside 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 | 68 |
| 30 CFR 56.14107 | Surface metal and nonmetal mines | 66 |
| 30 CFR 56.12004 | Surface metal and nonmetal mines | 57 |
| 30 CFR 56.20003 | Surface metal and nonmetal mines | 50 |
| 30 CFR 56.14100 | Surface metal and nonmetal mines | 35 |
| 30 CFR 50.30 | Reporting of accidents, injuries and illnesses | 33 |
| 30 CFR 56.12032 | Surface metal and nonmetal mines | 21 |
| 30 CFR 56.18002 | Surface metal and nonmetal mines | 19 |
| 30 CFR 56.12008 | Surface metal and nonmetal mines | 18 |
| 30 CFR 56.14132 | Surface metal and nonmetal mines | 17 |
| 30 CFR 56.12002 | Surface metal and nonmetal mines | 14 |
| 30 CFR 56.9300 | Surface metal and nonmetal mines | 14 |
| 30 CFR 56.14207 | Surface metal and nonmetal mines | 12 |
| 30 CFR 56.16001 | Surface metal and nonmetal mines | 12 |
| 30 CFR 56.11001 | Surface metal and nonmetal mines | 11 |
Injury and illness cases at mines in Riverside County, California
Accident reports by degree of injury, as the operator reported them to MSHA.
| Degree | Cases |
|---|---|
| Days away from work or restricted activity | 60 |
| No lost time, or an occupational illness | 23 |
What the accident reports at mines in Riverside County, California describe
Accident classification, as MSHA codes the circumstances that contributed most directly.
| Classification | Reports |
|---|---|
| Handling of materials | 28 |
| Slip or fall of person | 14 |
| Handtools (nonpowered) | 10 |
| Machinery | 9 |
| Powered haulage | 8 |
| Other | 6 |
| Striking or bumping | 5 |
| Disorders (repeated trauma) | 2 |
| Stepping or kneeling on object | 2 |
Equipment named in accident reports at mines in Riverside County, California
| Equipment | Reports |
|---|---|
| Hand tools (not powered) | 10 |
| Ore haulage trucks - off highway trucks | 6 |
| Hand tools (powered) | 5 |
| Front-end loader | 4 |
| Conveyor | 2 |
| Shovel | 2 |
| Welding machine | 2 |
| Tugger | 1 |
| Crusher | 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.