ACTIVE / OPERATOR PORTFOLIO

Monarch Mountain Minerals & Aggregates, LLC

Membership and operating status are from the latest MSHA Mines snapshot. Open a mine for its ownership history.

MSHA OPERATOR ID0122411

MINE PORTFOLIO

7 of 7 mines and facilities

2025-01-01 – 2026-10-18. Active records; production reporting is not required.

MineLocation / typeCoal · short tonsHours workedViolationsAccident recordsOn-site inspection hours
Aquilla4105521 · Active6/8 quarters reportedHill, TXSurface · MSHA: Construction Sand and Gravel050,4716124.5
CERRITO PELADO2900936 · Active6/8 quarters reportedSanta Fe, NMSurface · MSHA: Pumice010,447408.0
DENM0505193 · Active6/8 quarters reportedWeld, COSurface · MSHA: Construction Sand and Gravel019,693406.5
Glass Mountain Pumice0404165 · Active6/8 quarters reportedModoc, CASurface · MSHA: Pumice017,7280022.8
HOUM2 - Altair4105598 · Active6/8 quarters reportedColorado, TXSurface · MSHA: Sand, Common035,15311048.8
LASM-20952602873 · Active6/8 quarters reportedClark, NVSurface · MSHA: Construction Sand and Gravel041,46418030.5
MONARCH MOUNTAIN ACTON1700820 · Active5/8 quarters reportedYork, MESurface · MSHA: Construction Sand and Gravel09,1117016.8

LOCATION

Portfolio map

7 of 7 mines with usable MSHA coordinates. Select a marker to open a mine.

Mine coordinates

2025-01-01 – 2026-10-18Applies to production, safety and portfolio metrics. Silica samples have separate filters.

Violations

50

9 significant & substantial (S&S)

  1. 2025 Q13
  2. 2025 Q27
  3. 2025 Q32
  4. 2025 Q410
  5. 2026 Q17
  6. 2026 Q218
  7. 2026 Q33
  8. 2026 Q4 *0

Accident records

1

0 records classified as fatality

  1. 2025 Q10
  2. 2025 Q20
  3. 2025 Q30
  4. 2025 Q40
  5. 2026 Q10
  6. 2026 Q20
  7. 2026 Q31
  8. 2026 Q4 *0

Proposed penalties · USD

24,207.00

46 of 50 violations with amounts

  1. 2025 Q1453
  2. 2025 Q21,787
  3. 2025 Q31,630
  4. 2025 Q43,959
  5. 2026 Q16,565
  6. 2026 Q29,813
  7. 2026 Q3—
  8. 2026 Q4 *—

On-site inspection hours

157.75

27 inspections · 27 with hours

  1. 2025 Q116.25
  2. 2025 Q231.25
  3. 2025 Q35.00
  4. 2025 Q419.25
  5. 2026 Q125.25
  6. 2026 Q256.75
  7. 2026 Q34.00
  8. 2026 Q4 *0.00
Quarterly safety data
QuarterViolationsS&SProposed USDAccident recordsFatality recordsInspectionsOn-site hours
2025-Q130453.0000416.3
2025-Q2721,787.0000531.3
2025-Q3201,630.000015.0
2025-Q41023,959.0000319.3
2026-Q1726,565.0000425.3
2026-Q21839,813.0000756.8
2026-Q330—1024.0
2026-Q4 *00—0010.0
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.

SELECTED PORTFOLIO

1 linked controller.

Relationships reflect the selected mine status and current MSHA controller/operator fields.