MINE DETAILS

Mountaineer II Mine

ActiveUndergroundCoal (Bituminous)

MSHA MINE ID4609029

OPERATORMingo Logan Coal LLC

CONTROLLERCore Natural Resources Inc

LOCATIONLogan, WV

PUBLIC RECORD48,162 linked rows

LOCATION

Mine location

1 of 1 mine with usable MSHA coordinates. Select a marker to open a mine.

Mine coordinates

Mountaineer II Mine37.91194, -81.79861Open map ↗

Quarterly trends

2025 Q1 – 2026 Q4

JSON CSV

Database snapshot · 2026-10-17. MSHA quarterly production and employment reports.

Coal production

—

reported short tons

2025 Q1—No usable value reported
2025 Q2—No usable value reported
2025 Q3—No usable value reported
2025 Q4—No usable value reported
2026 Q1—No usable value reported
2026 Q2—No usable value reported
2026 Q3—No usable value reported
2026 Q4 *—No usable value reported

Hours worked

—

reported employee hours

2025 Q1—No usable value reported
2025 Q2—No usable value reported
2025 Q3—No usable value reported
2025 Q4—No usable value reported
2026 Q1—No usable value reported
2026 Q2—No usable value reported
2026 Q3—No usable value reported
2026 Q4 *—No usable value reported

Tons per hour

—

production ÷ hours worked

2025 Q1—No usable value reported
2025 Q2—No usable value reported
2025 Q3—No usable value reported
2025 Q4—No usable value reported
2026 Q1—No usable value reported
2026 Q2—No usable value reported
2026 Q3—No usable value reported
2026 Q4 *—No usable value reported

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

Quarterly production, employment and reporting coverage for Mountaineer II Mine
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 – 2026-10-17

Violations

950

166 significant & substantial (S&S)

2025 Q167
2025 Q2115
2025 Q3111
2025 Q4110
2026 Q1142
2026 Q2208
2026 Q3173
2026 Q4 *24

Accident records

0 records classified as fatality

2025 Q11
2025 Q23
2025 Q33
2025 Q42
2026 Q13
2026 Q23
2026 Q34
2026 Q4 *0

Proposed penalties · USD

921,018.00

864 of 950 violations with amounts

2025 Q173,010
2025 Q2185,798
2025 Q3121,569
2025 Q473,980
2026 Q1209,379
2026 Q2163,979
2026 Q393,303
2026 Q4 *—

On-site inspection hours

5,541.75

174 inspections · 174 with hours

2025 Q1415.50
2025 Q2689.50
2025 Q3728.25
2025 Q4672.75
2026 Q1819.50
2026 Q21,096.25
2026 Q31,043.00
2026 Q4 *77.00

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	Inspections	On-site hours
2025-Q1	67	9	73,010.00	1	20	415.5
2025-Q2	115	18	185,798.00	3	24	689.5
2025-Q3	111	11	121,569.00	3	24	728.3
2025-Q4	110	11	73,980.00	2	26	672.8
2026-Q1	142	40	209,379.00	3	22	819.5
2026-Q2	208	44	163,979.00	3	26	1,096.3
2026-Q3	173	31	93,303.00	4	28	1,043.0
2026-Q4 *	24	2	—	0	4	77.0

Most cited CFR sections

All violations issued in the selected period. Counts combine subsections.

Section	Violations	S&S
30 CFR 75.400Accumulation of combustible materials.	91	0
30 CFR 75.503Permissible electric face equipment; maintenance.	73	0
30 CFR 75.512Electric equipment; examination, testing and maintenance.	71	3
30 CFR 75.370Mine ventilation plan; submission and approval.	69	15
30 CFR 75.202Protection from falls of roof, face and ribs.	67	58
30 CFR 75.220Roof control plan.	44	11
30 CFR 75.333Ventilation controls.	32	0
30 CFR 75.517Power wires and cables; insulation and protection.	31	18
30 CFR 75.1403Other safeguards.	30	8
30 CFR 75.1731Maintenance of belt conveyors and belt conveyor entries.	29	1

Safety activity

violation2026-10-145098943
75.1731(b)
violation2026-10-145098942
75.400
inspection2026-10-13F005E96
103(i) Spot Inspections · 7.0 on-site hours
violation2026-10-135097342
75.601-1
violation2026-10-135098941
75.1106-3(a)(2)
violation2026-10-135098940
75.604(b)
violation2026-10-135098939
75.400
inspection2026-10-08F005E95
103(i) Spot Inspections · 5.5 on-site hours
violation2026-10-085184234
75.1505(a)
violation2026-10-085184233
75.351(c)(4)
violation2026-10-085184232
75.1600-2(b)
violation2026-10-085184231
75.1002(a)
violation2026-10-085184230
75.220(a)(1)
violation2026-10-085098938
75.503
violation2026-10-085098937
75.400
violation2026-10-075098936
75.1107-16(b)
violation2026-10-075098935
75.503
violation2026-10-075098934
75.503
violation2026-10-065184229
75.503
violation2026-10-065184228
75.601-1
violation2026-10-065184227
75.1725(a) · S&S
violation2026-10-065184226
75.220(a)(1)
violation2026-10-065184225
75.202(a) · S&S
violation2026-10-065098933
75.204(c)(1)
inspection2026-10-05F005E93
103(i) Spot Inspections · 6.0 on-site hours

Safety sources and definitions

MSHA Violations (issue date), Accidents (accident date), and Inspections (begin date). Snapshot 2026-10-17.

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.

EIA-923 · COAL RECEIPTS

Coal shipments and quality

Receipts reported by power plants and terminals, matched by MSHA mine ID.

REPORTED RECEIPTS · SHORT TONS—0 rows · 0 receiving plants

HEAT CONTENT · BTU/LB—Weighted by reported tons

SULFUR / ASH · % BY WEIGHT— / —Separate averages over measured receipts

DELIVERED COST · USD/TON—No price coverage

No receipts matched this mine in the selected period. EIA-923 does not cover all mine sales, exports or metallurgical coal shipments.

Delivered cost includes transport and is not mine revenue. Missing prices remain blank. * Fewer than three months are published in the selected quarter. Receipts reflect the months EIA has published; an unfinished quarter is not comparable with a full quarter. Portfolio matches use current ownership.

Coverage, sources and calculations

Reported coal receipts at EIA-923 power plants/terminals; this is not a census of mine shipments, exports or metallurgical sales.
Matches use only the published MSHA ID, normalized to seven digits. Unidentified mine origins remain in the source table but are not assigned to a mine.
Portfolio attribution uses current MSHA ownership, not ownership at the shipment date. Receipts and production can differ because of timing, stocks and coverage.
Quality means are weighted by positive reported tons with that measurement. Delivered cost uses only rows with published cost, positive heat and positive tons; missing/withheld costs are never zero-filled.
USD/ton = (cents/MMBtu ÷ 100) × MMBtu/ton. This is plant delivered cost, not mine sales price or revenue.
Receipt month is as published, including records supplied by annual respondents. Recent months are preliminary and subject to revision. Missing rows do not prove zero shipments.

Imported releases start 2008-01. This window includes 12 published months. EIA releases · Survey instructions

2026 · preliminary · EIA923_Schedules_2_3_4_5_M_07_2026_21SEP2026.xlsx · Page 5 Fuel Receipts and Costs
2025 · final · EIA923_Schedules_2_3_4_5_M_12_2025_Final.xlsx · Page 5 Fuel Receipts and Costs

EIA ANNUAL COAL REPORT · 2024

Coal prices and estimated revenue

Annual county prices and a production-based allocation of county coal sales.

FOB PRICE BENCHMARK · USD/TON123.83Published county average

ESTIMATED SALES · SHORT TONS1,086,200Allocated from published county sales

ESTIMATED COAL REVENUE · USD134,504,110Covered mines only · not reported revenue

ANNUAL PRODUCTION COVERED100.0%1 of 1 producing annual mine records

The estimate assumes each eligible mine receives its county-average price and shares county sales in proportion to production. Actual sales and prices can differ substantially. All producing annual records in this selection have estimates. Annual price data uses a separate window from the MSHA charts.

Mine / county	Annual production · tons	County FOB · USD/ton	Est. sales · tons	Est. coal revenue · USD	Basis / availability
Mountaineer Ii Mine4609029 · Logan, West Virginia	1,102,478	123.83	1,086,200	134,504,110	County allocation estimate11.31% of eligible county production24 eligible mines / 24 sales respondents

Method, assumptions and source records

This is an annual county-sales allocation, not reported mine or company revenue. Currency is nominal USD in the source year; quantities are short tons.
Mine share = same-year annual mine production / eligible same-county production. Estimated sales = published county sales × share. Estimated coal revenue = estimated sales × published county average FOB price.
The model assumes eligible mines share county sales in proportion to production and receive the county-average price. Matching mine counts is a check, not proof of identical respondents. Mine quality, contracts and sales timing can differ substantially. No statistical confidence interval is implied.
FOB excludes transport and insurance. EIA-923 delivered costs do not enter this model. No grade premium, state/national fallback, quarterly apportionment or carry-forward to a later year is applied.
Eligibility follows the source's production threshold and excludes preparation-only and refuse operations. Withheld values, inconsistent county counts and missing/ambiguous locations produce no estimate.
County sales are published in thousands of tons and prices to cents. Calculations retain precision, but the inputs are rounded and the allocation is approximate.
Portfolio attribution uses current MSHA ownership, not ownership during the sales year. Covered-mine sums exclude unavailable estimates and must not be read as whole-company revenue. Coverage denominators use the annual EIA mine-production release.

Sales-reporting threshold: 50,000 short tons per mine in 2024. Withheld sales or prices stay unavailable.

EIA Table 30 · county sales and FOB prices · EIA annual mine production · Release index

Annual report released November 19, 2025. Method: county-sales-allocation-v1. JSON and CSV preserve source row numbers and file checksums.

OWNERSHIP

Operator and controller history

Current ownership comes from MSHA Mines. Historical start and end dates come from MSHA Controller and Operator History.

CURRENT HIERARCHYCore Natural Resources Inc → Mingo Logan Coal LLC → Mountaineer II Mine

HISTORY RECORDS37 relationships

INTERVAL CHECK1 REVIEWcontroller/operator overlap

Jan 14, 2025—CURRENT / OPEN

Core Natural Resources InccontrolsMingo Logan Coal LLCoperatesMountaineer II Mine

msha-controller-operator-history · controller/operator co-tenure derived on mine 4609029

Mar 25, 2004—Jun 30, 1996

Ashland Inc et alcontrolsMingo Logan Coal LLCoperatesMountaineer II Mine

msha-controller-operator-history · controller/operator co-tenure derived on mine 4609029

Mar 25, 2004—Jan 13, 2025

Arch Resources InccontrolsMingo Logan Coal LLCoperatesMountaineer II Mine

msha-controller-operator-history · controller/operator co-tenure derived on mine 4609029

Other 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

366 historical accident/injury rows; 4 coded fatalities and 20,519 lost days across the published record.

ACCIDENT + INJURY RECORD51 since 2021

accidentsmine-production-quarterly

02 / COMPLIANCEwatch

Violations and penalties

7,378 violation rows across the full record; 1,563 carry an S&S flag and $5,357,619 appears in current assessed amounts.

ENFORCEMENT ACTIVITY2,361 since 2021

inspectionsviolationsassessed-violationsorders-107a

03 / HEALTHwatch

Occupational health samples

18,899 coal dust; 725 coal quartz; 678 noise. 0 personal-sample rows have a published C/E ratio above 1; 132 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 EXPOSURE20K samples

coal-dust-samplesquartz-samplesnoise-samples

04 / PRODUCTIONcontext

Quarterly production and employment

The source remains registered, but no mine-keyed quarterly production row was published.

NO CURRENT QUARTERNo published quarter

mine-production-quarterlymine-production-yearly

05 / LEGALwatch

Contests, conferences and decisions

2,466 contested-violation rows, 2,475 civil-penalty docket/decision rows, and 263 conference records linked by issuance number.

POST-ISSUANCE LIFECYCLE5,204 linked rows

conferencescontested-violationscivil-penalty-dockets-decisions

06 / 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 CONTEXT23 linked entities

contractor-production-quarterlycontractor-production-yearlyaccidentsviolations

07 / INSPECTIONScontext

Inspections

1,843 inspection events and 77K published inspection hours across the historical record.

OVERSIGHT COVERAGE525 since 2021

inspectionsviolations

HEALTH SAMPLING

Silica and quartz

Coal quartz, metal/nonmetal personal samples and area samples. Snapshot Oct 17, 2026. 725 silica records across the mine’s published history.

Matching records5959 coal · 0 personal · 0 area

Sample status50 not voided9 voided · 0 status not reported

Mean coal quartz concentration12.16 µg/m³50 eligible measurements · 0 missing concentration

Coal quartz concentration

Quarterly mean · µg/m³ · not-voided samples

2026-Q114.5723 measurements
2026-Q29.5917 measurements
2026-Q31110 measurements
2026-Q4*—0 measurements

— 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.

2026 · Jan 28, 2026–Sep 1, 2026
Date / sample	Dataset / analyte	Occupation / area	Measurement	Sample status	Published action
Sep 1, 202658595880 / lab 2026036383	Coal quartzQuartz	OCCUPATION CODE NOT FOUNDINTAKE AIR	4 µg/m³1.9% quartz	VoidedINVALID SAMPLE TYPE	Not reported
Sep 1, 202658595728 / lab 2026036343	Coal quartzQuartz	CONTINUOUS MINER OPERATORDESIGNATED OCCUPATION	8 µg/m³3.2% quartz	Not voided	Not reported
Sep 1, 202658596091 / lab 2026036386	Coal quartzQuartz	SHUTTLE CAR OPERATOR (STANDARD SIDE)NON DESIGNATED OCCUPATION	6 µg/m³3.9% quartz	Not voided	Not reported
Sep 1, 202658595753 / lab 2026036339	Coal quartzQuartz	ROOF BOLTER (TWIN HEAD) (RETURN SIDE)NON DESIGNATED OCCUPATION	10 µg/m³5.6% quartz	Not voided	Not reported
Sep 1, 202658596047 / lab 2026036347	Coal quartzQuartz	OCCUPATION CODE NOT FOUNDINTAKE AIR	4 µg/m³1.9% quartz	VoidedINVALID SAMPLE TYPE	Not reported
Sep 1, 202658595982 / lab 2026036394	Coal quartzQuartz	OCCUPATION CODE NOT FOUNDINTAKE AIR	0 µg/m³—% quartz	VoidedINVALID SAMPLE TYPE	Not reported
Sep 1, 202658595804 / lab 2026036355	Coal quartzQuartz	SHUTTLE CAR OPERATOR (STANDARD SIDE)NON DESIGNATED OCCUPATION	15 µg/m³7.9% quartz	Not voided	Not reported
Sep 1, 202658595877 / lab 2026036382	Coal quartzQuartz	ROOF BOLTER (TWIN HEAD) (RETURN SIDE)NON DESIGNATED OCCUPATION	14 µg/m³4.8% quartz	Not voided	Not reported
Sep 1, 202658595802 / lab 2026036375	Coal quartzQuartz	SHUTTLE CAR OPERATOR (STANDARD SIDE)NON DESIGNATED OCCUPATION	14 µg/m³9% quartz	VoidedMMU NOT IN PRODUCING STATUS	Not reported
Sep 1, 202658595668 / lab 2026036396	Coal quartzQuartz	CONTINUOUS MINER OPERATORDESIGNATED OCCUPATION	10 µg/m³6.6% quartz	Not voided	Not reported
Sep 1, 202658595885 / lab 2026036334	Coal quartzQuartz	SHUTTLE CAR OPERATOR (OFF STANDARD)NON DESIGNATED OCCUPATION	4 µg/m³3.3% quartz	VoidedMMU NOT IN PRODUCING STATUS	Not reported
Sep 1, 202658595972 / lab 2026036374	Coal quartzQuartz	CONTINUOUS MINER OPERATORDESIGNATED OCCUPATION	10 µg/m³5.8% quartz	Not voided	Not reported
Sep 1, 202658596061 / lab 2026036335	Coal quartzQuartz	CONTINUOUS MINER OPERATORDESIGNATED OCCUPATION	10 µg/m³5.1% quartz	Not voided	Not reported
Sep 1, 202658595851 / lab 2026036351	Coal quartzQuartz	CONTINUOUS MINER OPERATORDESIGNATED OCCUPATION	20 µg/m³6.5% quartz	Not voided	Not reported
Sep 1, 202658595890 / lab 2026036387	Coal quartzQuartz	CONTINUOUS MINER OPERATORDESIGNATED OCCUPATION	7 µg/m³3.9% quartz	Not voided	Not reported
May 12, 202658593305 / lab 2026020097	Coal quartzQuartz	SHUTTLE CAR OPERATOR (STANDARD SIDE)NON DESIGNATED OCCUPATION	10 µg/m³2.5% quartz	Not voided	Not reported
May 12, 202658593286 / lab 2026020162	Coal quartzQuartz	CONTINUOUS MINER OPERATORDESIGNATED OCCUPATION	16 µg/m³11.4% quartz	Not voided	Not reported
May 12, 202658593454 / lab 2026020173	Coal quartzQuartz	ROOF BOLTER (TWIN HEAD) (RETURN SIDE)NON DESIGNATED OCCUPATION	7 µg/m³4.9% quartz	Not voided	Not reported
May 12, 202658593727 / lab 2026020075	Coal quartzQuartz	CONTINUOUS MINER OPERATORDESIGNATED OCCUPATION	9 µg/m³4.6% quartz	Not voided	Not reported
May 12, 202658593645 / lab 2026020161	Coal quartzQuartz	OCCUPATION CODE NOT FOUNDINTAKE AIR	18 µg/m³4.2% quartz	VoidedINVALID SAMPLE TYPE	Not reported

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.

EIA MINE CONTEXT2024 record

ANNUAL COAL PRODUCTION1,102,478short tons

LABOR HOURS: 828,735
AVG EMPLOYEES: 349
SUPPLY REGION: Appalachia Central
UNION: No union code published
OPERATION: Mine only
COMPANY TYPE: Operating Subsidiary

1 published EIA row aggregated under this MSHA ID. Components remain available in JSON.

TITLE 30 CROSSWALKCurrent through 2026-08-19

30 CFR 75.1731Maintenance of belt conveyors and belt conveyor entries.1 recent row ↗30 CFR 75.400Accumulation of combustible materials.2 recent rows ↗30 CFR 75.601-1Short circuit protection; ratings and settings of circuit breakers.1 recent row ↗30 CFR 75.1106-3Storage of liquefied and nonliquefied compressed gas cylinders; requirements.1 recent row ↗30 CFR 75.604Permanent splicing of trailing cables.1 recent row ↗30 CFR 75.1505Escapeway maps.1 recent row ↗30 CFR 75.351Atmospheric monitoring systems.1 recent row ↗30 CFR 75.1600-2Communication facilities; working sections; installation and maintenance requirements; audible or visual alarms.1 recent row ↗

RECENT PUBLIC RECORDS

Recent violations and samples

Latest records retained for inspection; aggregates above use the full source history.

VIOLATIONS12 latest shown

Oct 14, 2026509894375.1731(b)Citation

Oct 14, 2026509894275.400Citation

Oct 13, 2026509734275.601-1Citation

Oct 13, 2026509894175.1106-3(a)(2)Citation

Oct 13, 2026509894075.604(b)Citation

Oct 13, 2026509893975.400Citation

Oct 8, 2026518423475.1505(a)Citation

Oct 8, 2026518423375.351(c)(4)Citation

OTHER HEALTH SAMPLES8 latest shown

Coal dust, noise and other contaminants. Silica records above ↑

Oct 14, 2026