MINE DETAILS
Grimes Rock a CalPortland Company
MSHA MINE ID0405432
LOCATION
Mine location
1 of 1 mine with usable MSHA coordinates. Select a marker to open a mine.
Mine coordinates
- Grimes Rock a CalPortland Company34.33472, -118.90944Open map ↗
Quarterly trends
2025 Q1 – 2026 Q4
Database snapshot · 2026-10-18. MSHA quarterly production and employment reports.
Coal production
0reported short tons
Hours worked
103,305reported employee hours
Tons per hour
0.00production ÷ hours worked
Missing values appear as —. Totals use available reports. Tons per hour requires production and hours for the same quarters and a nonzero hours total. * Striped bars mark partial mine coverage or an incomplete quarter. See the table for coverage.
Quarterly data and reporting coverage
| Quarter | Coal (short tons) | Hours worked | Tons / hour | Avg. employees | Coverage |
|---|---|---|---|---|---|
| 2025 Q1 | 0 | 15,523 | 0.00 | 16 | 1/1 mines reporting |
| 2025 Q2 | 0 | 17,553 | 0.00 | 28 | 1/1 mines reporting |
| 2025 Q3 | 0 | 16,333 | 0.00 | 16 | 1/1 mines reporting |
| 2025 Q4 | 0 | 18,370 | 0.00 | 16 | 1/1 mines reporting |
| 2026 Q1 | 0 | 18,567 | 0.00 | 16 | 1/1 mines reporting |
| 2026 Q2 | 0 | 16,959 | 0.00 | 28 | 1/1 mines reporting |
| 2026 Q3 | — | — | — | — | No report |
| 2026 Q4 | — | — | — | — | No report |
Safety and enforcement
2025-01-01 – 2026-10-18
Violations
186 significant & substantial (S&S)
Accident records
30 records classified as fatality
Proposed penalties · USD
4,027.0018 of 18 violations with amounts
On-site inspection hours
45.507 inspections · 7 with hours
Counts are published records, including contractor records. * The quarter was incomplete at the snapshot date; recent counts may rise as reports arrive. — means no reported amount or hours. Portfolio totals use current membership.
Quarterly safety data
| Quarter | Violations | S&S | Proposed USD | Accident records | Fatality records | Inspections | On-site hours |
|---|---|---|---|---|---|---|---|
| 2025-Q1 | 6 | 2 | 1,138.00 | 0 | 0 | 4 | 21.5 |
| 2025-Q2 | 2 | 1 | 418.00 | 0 | 0 | 0 | — |
| 2025-Q3 | 0 | 0 | — | 1 | 0 | 0 | — |
| 2025-Q4 | 7 | 3 | 1,472.00 | 0 | 0 | 1 | 14.0 |
| 2026-Q1 | 0 | 0 | — | 2 | 0 | 1 | 1.5 |
| 2026-Q2 | 3 | 0 | 999.00 | 0 | 0 | 1 | 8.5 |
| 2026-Q3 | 0 | 0 | — | 0 | 0 | 0 | — |
| 2026-Q4 * | 0 | 0 | — | 0 | 0 | 0 | — |
Most cited CFR sections
All violations issued in the selected period. Counts combine subsections.
Safety activity
56.12032 · $267.00 proposed
50.30(a) · $366.00 proposed
50.30(a) · $366.00 proposed
Regular Safety and Health Inspection · 8.5 on-site hours
POWERED HAULAGE · DAYS AWAY FROM WORK ONLY
Accident narrative
Mechanic was adjusting a wiper blade when their shirt or tool caught on conveyor belt pulling their arm into head pulley causing a dislocated elbow and fracture on ulna and missing finger nail.
Compliance Follow-up Inspection · 1.5 on-site hours
HANDLING OF MATERIALS · DAYS AWAY FROM WORK ONLY
Accident narrative
Employee was removing screens from shaker for cleaning when one of the screens caught the harness they were wearing causing them to fall and hurt a knee.
56.12028 · $398.00 proposed
56.12041 · $151.00 proposed
56.12028 · $151.00 proposed
56.14211(a) · S&S · $267.00 proposed
56.18002 · S&S · $177.00 proposed
56.20003(a) · S&S · $177.00 proposed
56.4101 · $151.00 proposed
Regular Safety and Health Inspection · 14.0 on-site hours
OTHER · DAYS RESTRICTED ACTIVITY ONLY
Accident narrative
Employee was bending over to pick up a piece of pipe when they felt a strain in their back. Employee did not pick up the pipe only hurt their back bending over.
56.14130(g) · S&S · $267.00 proposed
56.14100(a) · $151.00 proposed
Regular Safety and Health Inspection · 7.0 on-site hours
Compliance Follow-up Inspection · 1.5 on-site hours
56.4200(b)(2) · $151.00 proposed
56.4201(a)(2) · $151.00 proposed
Verbal Hazard Complaint Inspections · 7.8 on-site hours
56.14100(b) · $151.00 proposed
56.14100(a) · S&S · $267.00 proposed
Safety sources and definitions
MSHA Violations (issue date), Accidents (accident date), and Inspections (begin date). Snapshot 2026-10-18.
Counts describe published rows, including contractor records; accident records are not distinct incidents or numbers of people injured.
Zero means no matching records in the imported sources, not proof of no events. Historical coverage differs by source; absence before a source begins reporting is not a zero incident rate. Invalid or absent dates and records after the snapshot are excluded.
S&S means SIG_SUB=Y. Fatality records use DEGREE_INJURY_CD=01. Proposed penalties are not final assessed or paid amounts; missing dollar values are omitted.
Inspection hours are SUM_TOTAL_ON_SITE_HOURS attributed to the inspection start date, without supervisor/trainee hours. Missing hours are omitted; a started inspection may still be open.
Portfolio totals use current mine membership, including events before the current owner or operator's tenure.
CFR headings link to the current Title 30 index; they are not historical legal determinations.
OWNERSHIP
Operator and controller history
Current ownership comes from MSHA Mines. Historical start and end dates come from MSHA Controller and Operator History.
—
Taiheiyo Cement CorpcontrolsCalPortlandoperatesGrimes Rock a CalPortland Company
msha-controller-operator-history · controller/operator co-tenure derived on mine 0405432—
Russell CochrancontrolsGrimes Rock IncoperatesGrimes Rock a CalPortland Company
msha-controller-operator-history · controller/operator co-tenure derived on mine 0405432Other historical summaries · source-specific periods
RECORD SUMMARY
Production, safety and enforcement
These summaries use the periods stated on each card, independently of the reporting period above.
01 / SAFETYwatch
Accidents and injuries
15 historical accident/injury rows; 0 coded fatalities and 316 lost days across the published record.
ACCIDENT + INJURY RECORD3 since 2021
accidentsmine-production-quarterly02 / COMPLIANCEwatch
Violations and penalties
219 violation rows across the full record; 63 carry an S&S flag and $56,491 appears in current assessed amounts.
ENFORCEMENT ACTIVITY53 since 2021
inspectionsviolationsassessed-violationsorders-107a03 / HEALTHcontext
Occupational health samples
19 personal. 0 personal-sample rows have a published C/E ratio above 1; 0 noise rows have an action-level or PEL dose above 100%. These are separate measures, not a silica exceedance count. Silica results and sample status are shown separately.
OCCUPATIONAL EXPOSURE19 samples
personal-health-samples04 / PRODUCTIONcontext
Quarterly production and employment
17K employee hours and 28 summed average employees across reported subunits in the latest published quarter.
2026-Q20 tons
mine-production-quarterlymine-production-yearly05 / LEGALwatch
Contests, conferences and decisions
55 contested-violation rows, 58 civil-penalty docket/decision rows, and 30 conference records linked by issuance number.
POST-ISSUANCE LIFECYCLE143 linked rows
conferencescontested-violationscivil-penalty-dockets-decisions06 / CONTRACTORScontext
Contractors
Contractors are linked through this mine’s violation or accident records. Their production and hours cover all their operations, so they are not included in this mine’s totals.
ENTITY-LEVEL CONTEXT1 linked entities
contractor-production-quarterlycontractor-production-yearlyaccidentsviolations07 / INSPECTIONScontext
Inspections
88 inspection events and 1K published inspection hours across the historical record.
OVERSIGHT COVERAGE27 since 2021
inspectionsviolationsHEALTH SAMPLING
Silica and quartz
Coal quartz, metal/nonmetal personal samples and area samples. Snapshot Oct 18, 2026. 4 silica records across the mine’s published history.
Personal silica samples · concentration / limit
Quarterly mean · published C/E ratio
— No eligible measurements. * Quarter in progress. Means describe the available samples, not average exposure across the mine.
Quartz % is the sample’s quartz content; µg/m³ is its reported concentration. Personal C/E is the ratio to the limit published with that sample. Personal and area concentration units and void status are not specified in those source files.
| Date / sample | Dataset / analyte | Occupation / area | Measurement | Sample status | Published action |
|---|---|---|---|---|---|
| No silica records match these filters. Missing samples do not establish safe conditions. | |||||
Sources and interpretation
- Coal means use numeric concentrations from samples marked not voided, excluding control/invalid sample types and dates after the snapshot. Missing values remain null; reported zeroes remain zero.
- Quarterly means describe available samples, not mine-wide or worker-average exposure. Quarters with no eligible measurements remain empty; the current quarter is partial.
- Personal C/E is MSHA's published concentration-to-limit ratio. A value above 1 is not by itself a citation or a determination under the 2024 silica rule. Personal and area files do not publish a void-status field.
- Area records include bulk-dust analyses and are kept separate from personal exposure results. Their concentration units are not specified in the source dictionary.
- Missing samples do not establish safe conditions. Coal quartz percentage and concentration are separate measures. No compliance threshold is inferred for coal samples.
Coal quartz field definitions ↗Metal/nonmetal personal field definitions ↗Metal/nonmetal area field definitions ↗
EIA + TITLE 30
EIA production and cited regulations
EIA annual figures are reported separately from MSHA. Regulation links use the current eCFR snapshot.
Not present in the 2024 EIA coal workbook.
This can mean the operation is non-coal, inactive for the annual period, or outside the EIA-7A reporting population.
30 CFR 56.12032Inspection and cover plates.1 recent row ↗30 CFR 50.30Preparation and submission of MSHA Form 7000-2—Quarterly Employment and Coal Production Report.2 recent rows ↗30 CFR 56.12028Testing grounding systems.2 recent rows ↗30 CFR 56.12041Design of switches and starting boxes.1 recent row ↗30 CFR 56.14211Blocking equipment in a raised position.1 recent row ↗30 CFR 56.18002Examination of working places.1 recent row ↗30 CFR 56.20003Housekeeping.1 recent row ↗30 CFR 56.4101Warning signs.1 recent row ↗
RECENT PUBLIC RECORDS
Recent violations and samples
Latest records retained for inspection; aggregates above use the full source history.
516627656.12032Citation
516627550.30(a)Citation
516627450.30(a)Citation
516524356.12028Citation
516524256.12041Citation
516524156.12028Citation
516524056.14211(a)S&S
516523956.18002S&S
Coal dust, noise and other contaminants. Silica records above ↑
Unlisted Particulate, respirable, <1% QtzCleanup Man
C/E: 00.00Concentration: 0000.13 · limit: 0000.00Source unit unspecified
Respirable dust, <.1mgCleanup Man
C/E: 00.00Concentration: 0000.00 · limit: 0000.00Source unit unspecified
Respirable dust, <.1mgCleanup Man
C/E: 00.00Concentration: 0000.00 · limit: 0000.00Source unit unspecified
Respirable dust, <.1mgFlotation/Concentrator Oper.
C/E: 00.00Concentration: 0000.00 · limit: 0000.00Source unit unspecified
Respirable dust, <.1mgCleanup Man
C/E: 00.00Concentration: 0000.00 · limit: 0000.00Source unit unspecified
Unlisted Particulate, respirable, <1% QtzDry Screen Plant Operator
C/E: 00.00Concentration: 0000.13 · limit: 0000.00Source unit unspecified
Respirable dust, <.1mgLaborer, Bullgang
C/E: 00.00Concentration: 0000.00 · limit: 0000.00Source unit unspecified
Respirable dust, <.1mgLaborer, Bullgang
C/E: 00.00Concentration: 0000.00 · limit: 0000.00Source unit unspecified
SOURCE COVERAGE
Reporting dates and coverage
15 datasets contain linked records. Missing datasets are listed below.
DATASETROWSWINDOWSTATUS
Accident, Injuries, and Illnessessafety · contractors15Mar 10, 2003—Feb 25, 2026mine-keyed
Addresses of Recordidentity · logistics1Apr 18, 2000—Apr 18, 2000mine-keyed
Assessed Violationscompliance · legal217Apr 18, 2000—May 27, 2026mine-keyed
Civil Penalty Dockets and Decisionscompliance · legal58Dec 9, 2015—Mar 21, 2025mine-keyed
Coal Dust Sampleshealth · safety—No published rowsabsent / not applicable
Conferencescompliance · legal30Jan 8, 2002—Oct 4, 2024mine-keyed
Contested Violationscompliance · legal55May 28, 2014—Aug 23, 2024mine-keyed
Contractor Employment and Production — Quarterlycontractors · production · safety146Not published—Not publishedentity-linked
Contractor Employment and Production — Yearlycontractors · production · safety31Not published—Not publishedentity-linked
Controller and Operator Historyidentity · compliance2Apr 1, 2000—Dec 28, 2024mine-keyed
Mine Employment and Production — Quarterlyproduction · safety · compliance207Not published—Not publishedmine-keyed
Mine Employment and Production — Yearlyproduction · safety · compliance54Not published—Not publishedmine-keyed
Inspectionssafety · compliance88Apr 18, 2000—May 26, 2026mine-keyed
Minesidentity · production · logistics1Not published—Not publishedmine-keyed
Metal and Nonmetal Area Sampleshealth · safety—No published rowsabsent / not applicable
Metal and Nonmetal Personal Health Sampleshealth · safety19May 2, 2002—Nov 5, 2024mine-keyed
Noise Sampleshealth · safety · equipment—No published rowsabsent / not applicable
Quartz Samples — Coalhealth · safety—No published rowsabsent / not applicable
Violationscompliance · safety · legal219Apr 18, 2000—May 27, 2026mine-keyed
107(a) Orders Issuedsafety · compliance—No published rowsabsent / not applicable
NOTES
Limitations
- Contractor production is entity-level and is never represented as mine-attributable.
- Missing rows can mean no event, publication delay, identity mismatch, or inapplicability.