MINE DETAILS
Questa Mine & Mill
MSHA MINE ID2901267
LOCATION
Mine location
1 of 1 mine with usable MSHA coordinates. Select a marker to open a mine.
Mine coordinates
- Questa Mine & Mill36.68639, -105.53194Open map ↗
Quarterly trends
2025 Q1 – 2026 Q4
Database snapshot · 2026-10-18. MSHA quarterly production and employment reports.
Coal production
—reported short tons
Hours worked
—reported employee hours
Tons per hour
—production ÷ 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 | — | — | — | — | No report |
| 2025 Q2 | — | — | — | — | No report |
| 2025 Q3 | — | — | — | — | No report |
| 2025 Q4 | — | — | — | — | No report |
| 2026 Q1 | — | — | — | — | No report |
| 2026 Q2 | — | — | — | — | No report |
| 2026 Q3 | — | — | — | — | No report |
| 2026 Q4 | — | — | — | — | No report |
Safety and enforcement
2025-01-01 – 2026-10-18
Violations
00 significant & substantial (S&S)
Accident records
10 records classified as fatality
Proposed penalties · USD
—0 of 0 violations with amounts
On-site inspection hours
—0 inspections · 0 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 | 0 | 0 | — | 0 | 0 | 0 | — |
| 2025-Q2 | 0 | 0 | — | 0 | 0 | 0 | — |
| 2025-Q3 | 0 | 0 | — | 0 | 0 | 0 | — |
| 2025-Q4 | 0 | 0 | — | 0 | 0 | 0 | — |
| 2026-Q1 | 0 | 0 | — | 0 | 0 | 0 | — |
| 2026-Q2 | 0 | 0 | — | 1 | 0 | 0 | — |
| 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.
| Section | Violations | S&S |
|---|
No violation records in this period.
Safety activity
No matching records in this period.
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.
—
Chevron CorporationcontrolsChevron Mining IncoperatesQuesta Mine & Mill
msha-controller-operator-history · controller/operator co-tenure derived on mine 2901267—
Chevron CorporationcontrolsMolycorp IncoperatesQuesta Mine & Mill
msha-controller-operator-history · controller/operator co-tenure derived on mine 2901267—
Unocal CorpcontrolsMolycorp IncoperatesQuesta Mine & Mill
msha-controller-operator-history · controller/operator co-tenure derived on mine 2901267Other 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
169 historical accident/injury rows; 1 coded fatalities and 3,271 lost days across the published record.
ACCIDENT + INJURY RECORD1 since 2021
accidentsmine-production-quarterly02 / COMPLIANCEneutral
Violations and penalties
1,239 violation rows across the full record; 205 carry an S&S flag and $294,982 appears in current assessed amounts.
ENFORCEMENT ACTIVITY0 since 2021
inspectionsviolationsassessed-violationsorders-107a03 / HEALTHwatch
Occupational health samples
434 personal; 1 area. 32 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 EXPOSURE435 samples
personal-health-samplesarea-samples04 / PRODUCTIONcontext
Quarterly production and employment
35K employee hours and 65 summed average employees across reported subunits in the latest published quarter.
2015-Q40 tons
mine-production-quarterlymine-production-yearly05 / LEGALwatch
Contests, conferences and decisions
24 contested-violation rows, 27 civil-penalty docket/decision rows, and 88 conference records linked by issuance number.
POST-ISSUANCE LIFECYCLE139 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 CONTEXT34 linked entities
contractor-production-quarterlycontractor-production-yearlyaccidentsviolations07 / INSPECTIONScontext
Inspections
129 inspection events and 14K published inspection hours across the historical record.
OVERSIGHT COVERAGE0 since 2021
inspectionsviolationsHEALTH SAMPLING
Silica and quartz
Coal quartz, metal/nonmetal personal samples and area samples. Snapshot Oct 18, 2026. 102 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 56.4101Warning signs.1 recent row ↗30 CFR 57.12028Testing grounding systems.1 recent row ↗30 CFR 50.30Preparation and submission of MSHA Form 7000-2—Quarterly Employment and Coal Production Report.1 recent row ↗30 CFR 48.6Experienced miner training.1 recent row ↗30 CFR 57.4201Inspection.2 recent rows ↗30 CFR 57.12004Electrical conductors.1 recent row ↗30 CFR 57.14207Parking procedures for unattended equipment.1 recent row ↗30 CFR 57.12006Distribution boxes.2 recent rows ↗
RECENT PUBLIC RECORDS
Recent violations and samples
Latest records retained for inspection; aggregates above use the full source history.
877895856.4101Citation
886529257.12028Citation
886529150.30(a)Citation
886437548.6(a)Citation
886437357.4201(a)(2)Citation
886529057.12004Citation
886437257.4201(a)(1)Citation
886528957.14207Citation
Coal dust, noise and other contaminants. Silica records above ↑
Respirable dust, <.1mgDrill Helper
C/E: 00.00Concentration: 0000.00 · limit: 0000.00Source unit unspecified
Respirable dust, <.1mgCement/Concrete Man
C/E: 00.00Concentration: 0000.00 · limit: 0000.00Source unit unspecified
Respirable dust, <.1mgTruck Driver
C/E: 00.00Concentration: 0000.00 · limit: 0000.00Source unit unspecified
Unlisted Particulate, total, <1% QtzLaborer, Bullgang
C/E: 00.00Concentration: 0000.52 · limit: 0000.00Source unit unspecified
Unlisted Particulate, total, <1% QtzLaborer, Bullgang
C/E: 00.00Concentration: 0000.52 · limit: 0000.00Source unit unspecified
Unlisted Particulate, total, <1% QtzLaborer, Bullgang
C/E: 00.00Concentration: 0000.56 · limit: 0000.00Source unit unspecified
TC @ 160Motorman
C/E: 00.13Concentration: 0021.00 · limit: 0160.00Source unit unspecified
EC @ 160Motorman
C/E: 00.07Concentration: 0011.00 · limit: 0160.00Source unit unspecified
SOURCE COVERAGE
Reporting dates and coverage
16 datasets contain linked records. Missing datasets are listed below.
DATASETROWSWINDOWSTATUS
Accident, Injuries, and Illnessessafety · contractors169Feb 10, 2000—May 20, 2026mine-keyed
Addresses of Recordidentity · logistics1Dec 24, 2015—Dec 24, 2015mine-keyed
Assessed Violationscompliance · legal1,231Mar 2, 2000—Dec 22, 2015mine-keyed
Civil Penalty Dockets and Decisionscompliance · legal27Aug 26, 2003—Dec 1, 2015mine-keyed
Coal Dust Sampleshealth · safety—No published rowsabsent / not applicable
Conferencescompliance · legal88Nov 9, 2000—Apr 18, 2016mine-keyed
Contested Violationscompliance · legal24Mar 7, 2008—Jun 16, 2015mine-keyed
Contractor Employment and Production — Quarterlycontractors · production · safety5,066Not published—Not publishedentity-linked
Contractor Employment and Production — Yearlycontractors · production · safety1,017Not published—Not publishedentity-linked
Controller and Operator Historyidentity · compliance3Jan 1, 1950—Sep 1, 2007mine-keyed
Mine Employment and Production — Quarterlyproduction · safety · compliance252Not published—Not publishedmine-keyed
Mine Employment and Production — Yearlyproduction · safety · compliance63Not published—Not publishedmine-keyed
Inspectionssafety · compliance129Feb 29, 2000—Dec 21, 2015mine-keyed
Minesidentity · production · logistics1Not published—Not publishedmine-keyed
Metal and Nonmetal Area Sampleshealth · safety1May 6, 2009—May 6, 2009mine-keyed
Metal and Nonmetal Personal Health Sampleshealth · safety434Aug 23, 2000—Dec 4, 2013mine-keyed
Noise Sampleshealth · safety · equipment—No published rowsabsent / not applicable
Quartz Samples — Coalhealth · safety—No published rowsabsent / not applicable
Violationscompliance · safety · legal1,239Mar 2, 2000—Dec 22, 2015mine-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.