MINE DETAILS
Kennecott Keystone Underground
MSHA MINE ID4201392
LOCATION
Mine location
1 of 1 mine with usable MSHA coordinates. Select a marker to open a mine.
Mine coordinates
- Kennecott Keystone Underground40.56472, -112.10028Open map ↗
Quarterly trends
2025 Q1 – 2026 Q4
Database snapshot · 2026-10-13. MSHA quarterly production and employment reports.
Coal production
0reported short tons
Hours worked
184,020reported 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 | 30,692 | 0.00 | 65 | 1/1 mines reporting |
| 2025 Q2 | 0 | 31,434 | 0.00 | 69 | 1/1 mines reporting |
| 2025 Q3 | 0 | 32,199 | 0.00 | 71 | 1/1 mines reporting |
| 2025 Q4 | 0 | 31,309 | 0.00 | 69 | 1/1 mines reporting |
| 2026 Q1 | 0 | 31,277 | 0.00 | 67 | 1/1 mines reporting |
| 2026 Q2 | 0 | 27,109 | 0.00 | 62 | 1/1 mines reporting |
| 2026 Q3 | — | — | — | — | No report |
| 2026 Q4 | — | — | — | — | No report |
Safety and enforcement
2025-01-01 – 2026-10-13
Violations
10510 significant & substantial (S&S)
Accident records
101 records classified as fatality
Proposed penalties · USD
207,137.0094 of 105 violations with amounts
On-site inspection hours
514.2523 inspections · 23 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 | 25 | 3 | 66,523.00 | 2 | 0 | 4 | 47.5 |
| 2025-Q2 | 8 | 1 | 43,292.00 | 1 | 0 | 2 | 46.5 |
| 2025-Q3 | 15 | 0 | 17,973.00 | 3 | 0 | 4 | 60.5 |
| 2025-Q4 | 12 | 2 | 22,391.00 | 2 | 0 | 5 | 51.3 |
| 2026-Q1 | 19 | 2 | 19,954.00 | 2 | 1 | 2 | 144.3 |
| 2026-Q2 | 16 | 1 | 36,853.00 | 0 | 0 | 4 | 83.8 |
| 2026-Q3 | 10 | 1 | 151.00 | 0 | 0 | 2 | 80.5 |
| 2026-Q4 * | 0 | 0 | — | 0 | 0 | 0 | — |
Most cited CFR sections
All violations issued in the selected period. Counts combine subsections.
Safety activity
Spot Inspection · 21.0 on-site hours
49.6(a)(5) · $151.00 proposed
57.9101 · S&S
57.12032
57.12032
57.12032
57.3200
57.14100(b)
57.12004
Regular Safety and Health Inspection · 59.5 on-site hours
57.12032
47.41(a)
Compliance Follow-up Inspection · 4.0 on-site hours
Verbal Hazard Complaint Inspections · 2.5 on-site hours
57.6160(b)(3) · S&S · $6,037.00 proposed
57.14206(b) · $288.00 proposed
57.13021 · $151.00 proposed
57.15001 · $1,818.00 proposed
57.12032 · $1,818.00 proposed
57.12032 · $1,818.00 proposed
57.12018 · $4,047.00 proposed
57.12020 · $4,047.00 proposed
Verbal Hazard Complaint Inspections · 1.5 on-site hours
Regular Safety and Health Inspection · 75.8 on-site hours
57.14100(c) · $1,818.00 proposed
Safety sources and definitions
MSHA Violations (issue date), Accidents (accident date), and Inspections (begin date). Snapshot 2026-10-13.
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.
—
Rio Tinto GroupcontrolsKennecott Utah Copper LLCoperatesKennecott Keystone Underground
msha-controller-operator-history · controller/operator co-tenure derived on mine 4201392—
British Petroleum Company PLCcontrolsKennecott/New Mines Development DivisionoperatesKennecott Keystone Underground
msha-controller-operator-history · controller/operator co-tenure derived on mine 4201392—
Kennecott Copper CorpcontrolsKennecott Minerals CompanyoperatesKennecott Keystone Underground
msha-controller-operator-history · controller/operator co-tenure derived on mine 4201392Other 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
60 historical accident/injury rows; 1 coded fatalities and 719 lost days across the published record.
ACCIDENT + INJURY RECORD22 since 2021
accidentsmine-production-quarterly02 / COMPLIANCEwatch
Violations and penalties
277 violation rows across the full record; 36 carry an S&S flag and $352,584 appears in current assessed amounts.
ENFORCEMENT ACTIVITY196 since 2021
inspectionsviolationsassessed-violationsorders-107a03 / HEALTHwatch
Occupational health samples
65 personal; 4 area. 2 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 EXPOSURE69 samples
personal-health-samplesarea-samples04 / PRODUCTIONcontext
Quarterly production and employment
27K employee hours and 62 summed average employees across reported subunits in the latest published quarter.
2026-Q20 tons
mine-production-quarterlymine-production-yearly05 / LEGALwatch
Contests, conferences and decisions
32 contested-violation rows, 32 civil-penalty docket/decision rows, and 3 conference records linked by issuance number.
POST-ISSUANCE LIFECYCLE67 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 CONTEXT29 linked entities
contractor-production-quarterlycontractor-production-yearlyaccidentsviolations07 / INSPECTIONScontext
Inspections
120 inspection events and 4K published inspection hours across the historical record.
OVERSIGHT COVERAGE48 since 2021
inspectionsviolationsHEALTH SAMPLING
Silica and quartz
Coal quartz, metal/nonmetal personal samples and area samples. Snapshot Oct 13, 2026. 8 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 |
|---|---|---|---|---|---|
| 000000202603900000 | Metal/nonmetal personalQuartz, respirable, >1% Qtz | Mucking Mach. Operator | 0.19× published limitConcentration: 0000.14 · limit: 0000.74Source unit unspecified | Not reported | NO ACTIONInspection F043124 |
| 000000202603899900 | Metal/nonmetal personalQuartz, respirable, >1% Qtz | Roof Bolter, Rock | 0× published limitConcentration: 0000.25 · limit: 0000.00Source unit unspecified | Not reported | NO ACTIONInspection F043124 |
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 49.6Equipment and maintenance requirements.1 recent row ↗30 CFR 57.9101Operating speeds and control of equipment.1 recent row ↗30 CFR 57.12032Inspection and cover plates.4 recent rows ↗30 CFR 57.3200Correction of hazardous conditions.1 recent row ↗30 CFR 57.14100Safety defects; examination, correction and records.1 recent row ↗30 CFR 57.12004Electrical conductors.1 recent row ↗30 CFR 47.41Requirement for container labels.1 recent row ↗30 CFR 57.6160Main facilities.1 recent row ↗
RECENT PUBLIC RECORDS
Recent violations and samples
Latest records retained for inspection; aggregates above use the full source history.
990685649.6(a)(5)Citation
990685557.9101S&S
990685457.12032Citation
990685357.12032Citation
990685257.12032Citation
990685157.3200Citation
990685057.14100(b)Citation
990684957.12004Citation
Coal dust, noise and other contaminants. Silica records above ↑
Respirable dust, <.1mgRoad Grader Operator
C/E: 00.00Concentration: 0000.00 · limit: 0000.00Source unit unspecified
ORGANIC CARBONMucking Mach. Operator
C/E: 00.00Concentration: 0000.00 · limit: 0000.00Source unit unspecified
EC @ 160Mucking Mach. Operator
C/E: 00.00Concentration: 0000.00 · limit: 0160.00Source unit unspecified
TC from EC @ 160Truck Driver
C/E: 00.00Concentration: 0000.00 · limit: 0160.00Source unit unspecified
EC @ 160Truck Driver
C/E: 00.00Concentration: 0000.00 · limit: 0160.00Source unit unspecified
ORGANIC CARBONTruck Driver
C/E: 00.00Concentration: 0000.00 · limit: 0000.00Source unit unspecified
TC @ 160Mucking Mach. Operator
C/E: 00.00Concentration: 0000.00 · limit: 0160.00Source unit unspecified
TC from EC @ 160Mucking Mach. Operator
C/E: 00.00Concentration: 0000.00 · 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 · contractors60Nov 7, 2006—Mar 12, 2026mine-keyed
Addresses of Recordidentity · logistics1Aug 6, 2012—Aug 6, 2012mine-keyed
Assessed Violationscompliance · legal259Nov 21, 2006—Aug 31, 2026mine-keyed
Civil Penalty Dockets and Decisionscompliance · legal32Feb 21, 2013—Feb 17, 2026mine-keyed
Coal Dust Sampleshealth · safety—No published rowsabsent / not applicable
Conferencescompliance · legal3Feb 7, 2023—Mar 25, 2026mine-keyed
Contested Violationscompliance · legal32Feb 14, 2012—Feb 3, 2026mine-keyed
Contractor Employment and Production — Quarterlycontractors · production · safety5,897Not published—Not publishedentity-linked
Contractor Employment and Production — Yearlycontractors · production · safety1,332Not published—Not publishedentity-linked
Controller and Operator Historyidentity · compliance3Jan 1, 1950—May 8, 2006mine-keyed
Mine Employment and Production — Quarterlyproduction · safety · compliance167Not published—Not publishedmine-keyed
Mine Employment and Production — Yearlyproduction · safety · compliance41Not published—Not publishedmine-keyed
Inspectionssafety · compliance120Nov 21, 2006—Sep 10, 2026mine-keyed
Minesidentity · production · logistics1Not published—Not publishedmine-keyed
Metal and Nonmetal Area Sampleshealth · safety4May 7, 2024—Aug 30, 2026mine-keyed
Metal and Nonmetal Personal Health Sampleshealth · safety65Dec 11, 2012—Sep 18, 2026mine-keyed
Noise Sampleshealth · safety · equipment—No published rowsabsent / not applicable
Quartz Samples — Coalhealth · safety—No published rowsabsent / not applicable
Violationscompliance · safety · legal277Nov 21, 2006—Aug 31, 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.