ACTIVE / CONTROLLER PORTFOLIO

RRM Development Corporation; Mitsubishi Corp

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

MSHA CONTROLLER IDM11611

MINE PORTFOLIO

11 of 11 mines and facilities

2025-01-01 – 2026-10-17. Active records; production reporting is not required.

MineLocation / typeCoal · short tonsHours workedViolationsAccident recordsOn-site inspection hours
Banning0402815 · ActiveRiverside, CASurface · MSHA: Construction Sand and Gravel——1031.0
Cabazon0402774 · ActiveRiverside, CASurface · MSHA: Construction Sand and Gravel——2130.5
Corona0405887 · ActiveRiverside, CASurface · MSHA: Construction Sand and Gravel——5650.8
El Cajon Quarry0400133 · ActiveSan Diego, CASurface · MSHA: Crushed, Broken Granite——12046.0
Jean Plant2602520 · ActiveClark, NVSurface · MSHA: Construction Sand and Gravel——11041.3
Juniper Flats0405097 · ActiveRiverside, CASurface · MSHA: Construction Sand and Gravel——6033.5
Lucerne Valley0405690 · ActiveSan Bernardino, CASurface · MSHA: Construction Sand and Gravel——1016.0
Palmdale0404803 · ActiveLos Angeles, CASurface · MSHA: Construction Sand and Gravel——8134.5
Redlands0404652 · ActiveSan Bernardino, CASurface · MSHA: Construction Sand and Gravel——2042.5
Rialto0405392 · ActiveSan Bernardino, CASurface · MSHA: Construction Sand and Gravel——3145.3
Ridgecrest Rock Plant0404163 · ActiveKern, CASurface · MSHA: Construction Sand and Gravel——2018.3

LOCATION

Portfolio map

11 of 11 mines with usable MSHA coordinates. Select a marker to open a mine.

Mine coordinates

2025-01-01 – 2026-10-17Applies 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. violation5108629
    Jean Plant · 2602520

    56.14107(a)

  2. inspectionF0438ED
    Jean Plant · 2602520

    103 (g) Written Notification Hazard Complaint Inspectio · 0.0 on-site hours

  3. inspectionF0438EE
    Jean Plant · 2602520

    Regular Safety and Health Inspection · 0.0 on-site hours

  4. inspectionF04A768
    Cabazon · 0402774

    Impoundment Spot Inspection · 1.3 on-site hours

  5. inspectionF02C5AB
    Cabazon · 0402774

    Regular Safety and Health Inspection · 5.3 on-site hours

  6. inspectionF02B389
    Rialto · 0405392

    Regular Safety and Health Inspection · 17.5 on-site hours

  7. violation5166996
    Rialto · 0405392

    56.14112(b)

  8. accident220262640008
    Corona · 0405887

    HANDTOOLS (NONPOWERED) · DYS AWY FRM WRK & RESTRCTD ACT

    Accident narrative

    Swinging a sledgehammer on crusher bolts, felt pain in back.

  9. inspectionF04A75A
    Redlands · 0404652

    Regular Safety and Health Inspection · 7.5 on-site hours

  10. inspectionF04A758
    Banning · 0402815

    Impoundment Spot Inspection · 1.0 on-site hours

  11. inspectionF0177E4
    Palmdale · 0404803

    Regular Safety and Health Inspection · 8.0 on-site hours

  12. violation9890565
    Palmdale · 0404803

    56.23003(b) · $151.00 proposed

  13. violation9890564
    Palmdale · 0404803

    56.12008 · $151.00 proposed

  14. violation9890563
    Palmdale · 0404803

    56.12008 · $151.00 proposed

  15. accident220262330014
    Corona · 0405887

    MACHINERY · DAYS AWAY FROM WORK ONLY

    Accident narrative

    Miner was welding and debris came over EE's hood and into EE's left eye. Wasn't reported to management until 8/18/2026.

  16. inspectionF03716B
    Ridgecrest Rock Plant · 0404163

    Regular Safety and Health Inspection · 4.0 on-site hours

  17. inspectionF039E3F
    Lucerne Valley · 0405690

    Regular Safety and Health Inspection · 4.0 on-site hours

  18. inspectionF02C59D
    Corona · 0405887

    Spot Inspection · 0.0 on-site hours

  19. violation5166864
    Corona · 0405887

    50.20-1 · $151.00 proposed

  20. violation5166688
    El Cajon Quarry · 0400133

    46.5(a) · S&S · $5,716.00 proposed

  21. violation5166687
    El Cajon Quarry · 0400133

    56.12004 · S&S · $1,037.00 proposed

  22. inspectionF017890
    El Cajon Quarry · 0400133

    Regular Safety and Health Inspection · 8.0 on-site hours

  23. inspectionF039E3B
    Banning · 0402815

    Impoundment Spot Inspection · 0.5 on-site hours

  24. accident220261680001
    Cabazon · 0402774

    MACHINERY · NO DYS AWY FRM WRK,NO RSTR ACT

    Accident narrative

    Miner was working in a conveyor head box and had set a 1-ton Lever hoist on the head pulley above EE. When EE bent over, EE's hardhat fell off and the lever hoist slid off the head pulley and struck EE in the head.

  25. accident220261680022
    Palmdale · 0404803

    SLIP OR FALL OF PERSON · DAYS AWAY FROM WORK ONLY

    Accident narrative

    Miner was exiting a shaker deck, stepped wrong and rolled R-ankle.

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.

SELECTED PORTFOLIO

1 linked operator.

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