Data / Mines / California / Stone mines

Stone mines in California: 109 open mines and MSHA citations

MSHA lists 109 open stone mines in California, run by 81 operators and employing 2,312 people. Since January 1, 2022 its inspectors issued 3,482 citations and orders there with $2,414,729 in proposed penalties, and operators reported 322 injury or illness cases, 3 of them fatal. The operators with the most open mines are Kernen Construction; CalPortland Company; Cemex Construction Materials Pacific, LLC. Data from MSHA, November 6, 2026.

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Open mines

109

Operators

81

Employees

2,312

Active

76

Intermittent

30

Temporarily Idled

3

Mines run by individuals, counted and not listed

5

Citations and orders since January 1, 2022

3,482

Significant and substantial

683 (19.6%)

Closure orders

98

High negligence or reckless

198

Proposed penalties

$2,414,729

Amount paid so far

$2,022,301

Inspections

1,354

Inspector hours on site

14,254

Citations per inspection

2.57 (all mines 2.30)

Accident reports

355

Injury and illness cases

322

Fatalities

3

Latest MSHA record

November 4, 2026

Operators with the most open mines in California

Ranked by open mines, then by citations. Sole proprietors and individuals are not listed.

Operators with the most citations in 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.

Main commodities

Citations and injury cases by year

Calendar years since 2022; 2026 runs to the date of the MSHA files.

Standards cited most at stone mines in California

Sections of Title 30 of the Code of Federal Regulations named on the citations, with the part each belongs to.

Injury and illness cases at stone mines in California

Accident reports by degree of injury, as the operator reported them to MSHA.

What the accident reports at stone mines in California describe

Accident classification, as MSHA codes the circumstances that contributed most directly.

Equipment named in accident reports at stone mines in California

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.