ACTIVE / OPERATOR PORTFOLIO

U.S. Silica Company, LLC

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

MSHA OPERATOR IDL14417

MINE PORTFOLIO

24 of 24 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
Berkeley Plant4602805 · Active6/8 quarters reportedMorgan, WVSurface · MSHA: Ground Silica0187,508161250.3
Celatom Mine3503237 · Active6/8 quarters reportedMalheur, ORSurface · MSHA: Diatomaceous Earth (Diatomite)071,7481117.8
Celatom Plant3503236 · Active6/8 quarters reportedMalheur, ORFacility · MSHA: Diatomaceous Earth (Diatomite)0194,9033137.0
Clark Operations2600677 · Active6/8 quarters reportedStorey, NVSurface · MSHA: Diatomaceous Earth (Diatomite)0197,59114037.8
Colado Mine2600672 · Active6/8 quarters reportedPershing, NVSurface · MSHA: Diatomaceous Earth (Diatomite)088,6344132.5
Colado Plant2600680 · Active6/8 quarters reportedPershing, NVSurface · MSHA: Diatomaceous Earth (Diatomite)0315,74818271.5
COLUMBIA PLANT3800138 · Active6/8 quarters reportedLexington, SCSurface · MSHA: Sand, Industrial NEC0167,718640256.5
Dubberly Plant1600489 · Active6/8 quarters reportedWebster, LASurface · MSHA: Construction Sand and Gravel051,1164050.5
EP Engineered Clays Corporation2200415 · Active6/8 quarters reportedHinds, MSFacility · MSHA: Clay, Ceramic, Refractory Mnls.0257,89411269.0
Fernley Operations2601950 · Active6/8 quarters reportedChurchill, NVSurface · MSHA: Diatomaceous Earth (Diatomite)095,2929048.8
FOWLKES MINE2200460 · Active6/8 quarters reportedMonroe, MSSurface · MSHA: Bentonite02,4561040.0
Hurtsboro Plant0100617 · Active6/8 quarters reportedRussell, ALSurface · MSHA: Construction Sand and Gravel033,4705045.5
Jackson Plant4002937 · Active6/8 quarters reportedMadison, TNFacility · MSHA: Sand, Industrial NEC035,4440035.3
Mapleton Depot Plant3603122 · Active6/8 quarters reportedHuntingdon, PASurface · MSHA: Sand, Industrial NEC0162,55482136.5
Mauricetown Plant2800526 · Active6/8 quarters reportedCumberland, NJSurface · MSHA: Sand, Industrial NEC096,3946133.3
Middleton Operations4002968 · Active6/8 quarters reportedHardeman, TNSurface · MSHA: Common Clays NEC0220,0580051.8
Mill Creek Plant #373400377 · Active6/8 quarters reportedJohnston, OKSurface · MSHA: Sand, Industrial NEC079,6534029.3
Mill Creek Plant #393400836 · Active6/8 quarters reportedJohnston, OKSurface · MSHA: Crushed, Broken Sandstone0116,67914358.0
Millen Plant0901232 · Active6/8 quarters reportedJenkins, GAFacility · MSHA: Kaolin and Ball Clay095,8351037.8
Montpelier Plant4402829 · Active6/8 quarters reportedHanover, VASurface · MSHA: Aplite080,8175097.5
Ottawa Plant1101013 · Active6/8 quarters reportedLa Salle, ILSurface · MSHA: Ground Silica0455,548774261.3
Pacific Plant2300544 · Active6/8 quarters reportedSt Louis, MOSurface · MSHA: Quartz, Ground0174,13211186.3
Port Elizabeth Plant2800510 · Active6/8 quarters reportedCumberland, NJSurface · MSHA: Construction Sand and Gravel02,9601012.5
Rockwood Plant2000608 · Active6/8 quarters reportedWayne, MISurface · MSHA: Sand, Industrial NEC060,15810081.5

LOCATION

Portfolio map

24 of 24 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

287

38 significant & substantial (S&S)

  1. 2025 Q156
  2. 2025 Q226
  3. 2025 Q349
  4. 2025 Q443
  5. 2026 Q135
  6. 2026 Q243
  7. 2026 Q335
  8. 2026 Q4 *0

Accident records

19

0 records classified as fatality

  1. 2025 Q12
  2. 2025 Q22
  3. 2025 Q32
  4. 2025 Q43
  5. 2026 Q15
  6. 2026 Q22
  7. 2026 Q33
  8. 2026 Q4 *0

Proposed penalties · USD

112,008.00

275 of 287 violations with amounts

  1. 2025 Q121,687
  2. 2025 Q28,239
  3. 2025 Q329,813
  4. 2025 Q425,798
  5. 2026 Q17,971
  6. 2026 Q211,291
  7. 2026 Q37,209
  8. 2026 Q4 *—

On-site inspection hours

1,877.75

161 inspections · 161 with hours

  1. 2025 Q1342.00
  2. 2025 Q2286.50
  3. 2025 Q3248.75
  4. 2025 Q4276.50
  5. 2026 Q1249.00
  6. 2026 Q2261.25
  7. 2026 Q3206.75
  8. 2026 Q4 *7.00
Quarterly safety data
QuarterViolationsS&SProposed USDAccident recordsFatality recordsInspectionsOn-site hours
2025-Q156821,687.002027342.0
2025-Q22638,239.002021286.5
2025-Q349429,813.002023248.8
2025-Q443825,798.003023276.5
2026-Q13557,971.005019249.0
2026-Q243411,291.002022261.3
2026-Q33567,209.003024206.8
2026-Q4 *00—0027.0

Most cited CFR sections

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

Safety activity

  1. violation9890774
    Fernley Operations · 2601950

    56.12032 · $151.00 proposed

  2. violation9890773
    Fernley Operations · 2601950

    47.41(a) · $151.00 proposed

  3. inspectionF021E56
    Fernley Operations · 2601950

    Regular Safety and Health Inspection · 22.5 on-site hours

  4. violation5106150
    Clark Operations · 2600677

    56.12068 · S&S · $1,037.00 proposed

  5. violation5106149
    Clark Operations · 2600677

    56.23003(b) · $151.00 proposed

  6. violation5106148
    Clark Operations · 2600677

    56.12028 · $151.00 proposed

  7. violation5106147
    Clark Operations · 2600677

    56.14100(b) · $151.00 proposed

  8. violation5106146
    Clark Operations · 2600677

    56.11001 · $151.00 proposed

  9. inspectionF039817
    Clark Operations · 2600677

    Regular Safety and Health Inspection · 18.3 on-site hours

  10. inspectionF0280E7
    COLUMBIA PLANT · 3800138

    Verbal Hazard Complaint Inspections · 6.0 on-site hours

  11. violation5063271
    COLUMBIA PLANT · 3800138

    56.14100(c) · $226.00 proposed

  12. violation5063270
    COLUMBIA PLANT · 3800138

    56.20003(a) · $151.00 proposed

  13. inspectionF02C4BC
    FOWLKES MINE · 2200460

    Regular Safety and Health Inspection · 5.5 on-site hours

  14. inspection6920266
    Middleton Operations · 4002968

    Regular Safety and Health Inspection · 23.0 on-site hours

  15. inspectionF026901
    Millen Plant · 0901232

    Regular Safety and Health Inspection · 15.5 on-site hours

  16. inspectionF01C809
    Colado Mine · 2600672

    Regular Safety and Health Inspection · 6.0 on-site hours

  17. inspectionF031814
    EP Engineered Clays Corporation · 2200415

    Compliance Follow-up Inspection · 1.0 on-site hours

  18. inspectionF0374DE
    Mill Creek Plant #37 · 3400377

    Regular Safety and Health Inspection · 9.0 on-site hours

  19. violation9349154
    Colado Plant · 2600680

    56.20003(a) · $226.00 proposed

  20. violation9349153
    Colado Plant · 2600680

    56.12032 · $151.00 proposed

  21. violation9349152
    Colado Plant · 2600680

    56.11001 · S&S · $1,126.00 proposed

  22. accident220260050010
    Mapleton Depot Plant · 3603122

    SLIP OR FALL OF PERSON · DAYS RESTRICTED ACTIVITY ONLY

    Accident narrative

    The employee fell while traversing an irregular surface. They put their arms out to catch themselves and sustained a closed fracture to the left radius and ulna.

  23. violation9349151
    Colado Plant · 2600680

    56.14100(b) · $151.00 proposed

  24. violation9349150
    Colado Plant · 2600680

    56.14100(b) · $151.00 proposed

  25. violation9349149
    Colado Plant · 2600680

    56.14107(a) · S&S · $1,679.00 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.

SELECTED PORTFOLIO

1 linked controller.

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