ACTIVE / OPERATOR PORTFOLIO

Robertson's

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

MSHA OPERATOR IDL14361

MINE PORTFOLIO

11 of 11 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
Banning0402815 · Active6/8 quarters reportedRiverside, CASurface · MSHA: Construction Sand and Gravel033,0671031.0
Cabazon0402774 · Active6/8 quarters reportedRiverside, CASurface · MSHA: Construction Sand and Gravel073,4342130.5
Corona0405887 · Active6/8 quarters reportedRiverside, CASurface · MSHA: Construction Sand and Gravel062,8685650.8
El Cajon Quarry0400133 · Active6/8 quarters reportedSan Diego, CASurface · MSHA: Crushed, Broken Granite064,11812046.0
Jean Plant2602520 · Active6/8 quarters reportedClark, NVSurface · MSHA: Construction Sand and Gravel036,34911041.3
Juniper Flats0405097 · Active6/8 quarters reportedRiverside, CASurface · MSHA: Construction Sand and Gravel042,7216033.5
Lucerne Valley0405690 · Active6/8 quarters reportedSan Bernardino, CASurface · MSHA: Construction Sand and Gravel034,2351016.0
Palmdale0404803 · Active6/8 quarters reportedLos Angeles, CASurface · MSHA: Construction Sand and Gravel035,6068134.5
Redlands0404652 · Active6/8 quarters reportedSan Bernardino, CASurface · MSHA: Construction Sand and Gravel030,6652042.5
Rialto0405392 · Active6/8 quarters reportedSan Bernardino, CASurface · MSHA: Construction Sand and Gravel062,1983145.3
Ridgecrest Rock Plant0404163 · Active6/8 quarters reportedKern, CASurface · MSHA: Construction Sand and Gravel09,9692018.3

LOCATION

Portfolio map

11 of 11 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

53

10 significant & substantial (S&S)

  1. 2025 Q114
  2. 2025 Q29
  3. 2025 Q37
  4. 2025 Q46
  5. 2026 Q13
  6. 2026 Q28
  7. 2026 Q35
  8. 2026 Q4 *1

Accident records

9

0 records classified as fatality

  1. 2025 Q11
  2. 2025 Q20
  3. 2025 Q31
  4. 2025 Q42
  5. 2026 Q10
  6. 2026 Q23
  7. 2026 Q32
  8. 2026 Q4 *0

Proposed penalties · USD

14,812.00

51 of 53 violations with amounts

  1. 2025 Q12,536
  2. 2025 Q21,393
  3. 2025 Q31,057
  4. 2025 Q4906
  5. 2026 Q1615
  6. 2026 Q27,701
  7. 2026 Q3604
  8. 2026 Q4 *—

On-site inspection hours

389.50

59 inspections · 59 with hours

  1. 2025 Q185.00
  2. 2025 Q270.25
  3. 2025 Q335.00
  4. 2025 Q460.00
  5. 2026 Q153.25
  6. 2026 Q237.50
  7. 2026 Q348.50
  8. 2026 Q4 *0.00
Quarterly safety data
QuarterViolationsS&SProposed USDAccident recordsFatality recordsInspectionsOn-site hours
2025-Q11432,536.00101185.0
2025-Q2911,393.0000870.3
2025-Q3711,057.0010735.0
2025-Q460906.0020860.0
2026-Q132615.0000953.3
2026-Q2837,701.0030537.5
2026-Q350604.0020948.5
2026-Q4 *10—0020.0

Most cited CFR sections

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

Safety activity

  1. violation9509696
    Corona · 0405887

    56.20003(a) · $151.00 proposed

  2. inspectionF01647A
    Cabazon · 0402774

    Compliance Follow-up Inspection · 3.0 on-site hours

  3. inspectionF014E72
    Cabazon · 0402774

    Regular Safety and Health Inspection · 5.0 on-site hours

  4. violation5165244
    Cabazon · 0402774

    56.14100(b) · $151.00 proposed

  5. inspectionF014E6B
    Redlands · 0404652

    Regular Safety and Health Inspection · 11.0 on-site hours

  6. violation5165088
    Juniper Flats · 0405097

    56.14112(b) · $151.00 proposed

  7. violation5165087
    Juniper Flats · 0405097

    56.14112(b) · $151.00 proposed

  8. inspectionF013155
    Juniper Flats · 0405097

    Regular Safety and Health Inspection · 13.5 on-site hours

  9. accident220253170345
    Rialto · 0405392

    STRIKING OR BUMPING · DYS AWY FRM WRK & RESTRCTD ACT

    Accident narrative

    Miner bumped EE's head on equipment frame exiting a skid steer. Miner was wearing a hardhat.

  10. violation9890542
    Palmdale · 0404803

    56.12032 · $151.00 proposed

  11. violation5103019
    Jean Plant · 2602520

    47.32 · $151.00 proposed

  12. inspectionF0177C1
    Palmdale · 0404803

    Regular Safety and Health Inspection · 6.0 on-site hours

  13. inspectionF023ED0
    Jean Plant · 2602520

    Regular Safety and Health Inspection · 7.8 on-site hours

  14. inspectionF017868
    Banning · 0402815

    Regular Safety and Health Inspection · 6.5 on-site hours

  15. inspectionF017869
    Banning · 0402815

    Impoundment Spot Inspection · 0.5 on-site hours

  16. violation5165483
    Banning · 0402815

    56.12004 · $151.00 proposed

  17. violation5165077
    Cabazon · 0402774

    56.14130(c)(3) · $151.00 proposed

  18. inspectionF01314E
    Cabazon · 0402774

    Regular Safety and Health Inspection · 15.5 on-site hours

  19. inspectionF017866
    Rialto · 0405392

    Regular Safety and Health Inspection · 8.3 on-site hours

  20. violation5165480
    Rialto · 0405392

    56.12004 · $151.00 proposed

  21. inspectionF0156D6
    Banning · 0402815

    Impoundment Spot Inspection · 1.0 on-site hours

  22. inspectionF027887
    Ridgecrest Rock Plant · 0404163

    Regular Safety and Health Inspection · 2.3 on-site hours

  23. accident220252060001
    Corona · 0405887

    HANDTOOLS (NONPOWERED) · NO DYS AWY FRM WRK,NO RSTR ACT

    Accident narrative

    Miner struck thumb with a hammer while trying to unstick a valve.

  24. inspectionF014E5A
    Lucerne Valley · 0405690

    Compliance Follow-up Inspection · 1.0 on-site hours

  25. violation9890464
    Palmdale · 0404803

    56.12008 · $151.00 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.