MSHA DATABASEMSHA records · 15 contributing sources · snapshot Oct 13, 2026

MINE DETAILS

Mill Creek Plant #39

ActiveSurfaceCrushed, Broken Sandstone
MSHA MINE ID3400836
LOCATIONJohnston, OK
PUBLIC RECORD2,256 linked rows

LOCATION

Mine location

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

Mine coordinates

2025-01-01 – 2026-10-13Applies to production, safety and portfolio metrics. Silica samples have separate filters.

Violations

14

3 significant & substantial (S&S)

  1. 2025 Q10
  2. 2025 Q21
  3. 2025 Q30
  4. 2025 Q44
  5. 2026 Q11
  6. 2026 Q20
  7. 2026 Q38
  8. 2026 Q4 *0

Accident records

3

0 records classified as fatality

  1. 2025 Q11
  2. 2025 Q21
  3. 2025 Q30
  4. 2025 Q40
  5. 2026 Q10
  6. 2026 Q20
  7. 2026 Q31
  8. 2026 Q4 *0

Proposed penalties · USD

2,727.00

10 of 14 violations with amounts

  1. 2025 Q1—
  2. 2025 Q2151
  3. 2025 Q3—
  4. 2025 Q4893
  5. 2026 Q11,037
  6. 2026 Q2—
  7. 2026 Q3646
  8. 2026 Q4 *—

On-site inspection hours

58.00

5 inspections · 5 with hours

  1. 2025 Q11.50
  2. 2025 Q218.25
  3. 2025 Q3—
  4. 2025 Q412.75
  5. 2026 Q14.00
  6. 2026 Q2—
  7. 2026 Q321.50
  8. 2026 Q4 *—
Quarterly safety data
QuarterViolationsS&SProposed USDAccident recordsFatality recordsInspectionsOn-site hours
2025-Q100—1011.5
2025-Q210151.0010118.3
2025-Q300—000—
2025-Q440893.0000112.8
2026-Q1111,037.000014.0
2026-Q200—000—
2026-Q382646.0010121.5
2026-Q4 *00—000—

Most cited CFR sections

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

Safety activity

  1. accident220262300012

    MACHINERY · NO DYS AWY FRM WRK,NO RSTR ACT

    Accident narrative

    An employee received a laceration on left leg, just above the knee, when a handheld grinder inadvertently made contact. The laceration required seven stitches to close.

  2. violation5177952

    56.14100(c) · S&S

  3. violation5177951

    56.11012 · $193.00 proposed

  4. violation5177950

    56.9300(b) · $151.00 proposed

  5. violation5177949

    56.12032 · $151.00 proposed

  6. violation5177948

    56.11008

  7. violation5177947

    56.14112(b)

  8. violation5177946

    56.11003 · $151.00 proposed

  9. violation5177945

    56.20003(c) · S&S

  10. inspectionF03C329

    Regular Safety and Health Inspection · 21.5 on-site hours

  11. violation5004296

    56.6306(f)(1) · S&S · $1,037.00 proposed

  12. inspectionF0086AB

    103 (g) Written Notification Hazard Complaint Inspectio · 4.0 on-site hours

  13. violation5170609

    56.14101(a)(2) · $151.00 proposed

  14. violation5170608

    56.4200(b)(2) · $398.00 proposed

  15. violation5170607

    56.12068 · $193.00 proposed

  16. violation5170606

    56.14100(b) · $151.00 proposed

  17. inspectionF028A51

    Regular Safety and Health Inspection · 12.8 on-site hours

  18. violation5004405

    56.11012 · $151.00 proposed

  19. inspectionF0157A3

    Regular Safety and Health Inspection · 18.3 on-site hours

  20. accident220252510020

    HANDLING OF MATERIALS · DYS AWY FRM WRK & RESTRCTD ACT

    Accident narrative

    The employee's leg was struck by a shifting slurry hose while disconnecting a coupling. They went to a doctor and was diagnosed with a tear in their ACL. The injured employee had surgery on 9/4/25 which made this injury reportable.

  21. accident220250070012

    OTHER · INJURIES INVOLVNG NONEMPLOYEES

    Accident narrative

    Customer truck driver found unresponsive in the cab of the customer truck driver's truck.

  22. inspection6937099

    Non-Chargeable Accident Investigation · 1.5 on-site hours

Safety sources and definitions

MSHA Violations (issue date), Accidents (accident date), and Inspections (begin date). Snapshot 2026-10-13.

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.

OWNERSHIP

Operator and controller history

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

CURRENT HIERARCHYUSS Holdings Inc → U.S. Silica Company, LLC → Mill Creek Plant #39
HISTORY RECORDS39 relationships
INTERVAL CHECKPASScontroller/operator overlap
—

USS Holdings InccontrolsU.S. Silica Company, LLCoperatesMill Creek Plant #39

msha-controller-operator-history · controller/operator co-tenure derived on mine 3400836
—

Rio Tinto GroupcontrolsU S Silica CompanyoperatesMill Creek Plant #39

msha-controller-operator-history · controller/operator co-tenure derived on mine 3400836
—

ITT CorpcontrolsPennsylvania Glass Sand CorpoperatesMill Creek Plant #39

msha-controller-operator-history · controller/operator co-tenure derived on mine 3400836
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

34 historical accident/injury rows; 0 coded fatalities and 269 lost days across the published record.

ACCIDENT + INJURY RECORD7 since 2021
accidentsmine-production-quarterly
02 / COMPLIANCEwatch

Violations and penalties

154 violation rows across the full record; 28 carry an S&S flag and $22,547 appears in current assessed amounts.

ENFORCEMENT ACTIVITY29 since 2021
inspectionsviolationsassessed-violationsorders-107a
03 / HEALTHwatch

Occupational health samples

78 personal. 1 personal-sample rows have a published C/E ratio above 1; 0 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 EXPOSURE78 samples
personal-health-samples
04 / PRODUCTIONcontext

Quarterly production and employment

21K employee hours and 39 summed average employees across reported subunits in the latest published quarter.

2026-Q20 tons
mine-production-quarterlymine-production-yearly
05 / LEGALwatch

Contests, conferences and decisions

32 contested-violation rows, 34 civil-penalty docket/decision rows, and 14 conference records linked by issuance number.

POST-ISSUANCE LIFECYCLE80 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 CONTEXT12 linked entities
contractor-production-quarterlycontractor-production-yearlyaccidentsviolations
07 / INSPECTIONScontext

Inspections

78 inspection events and 1K published inspection hours across the historical record.

OVERSIGHT COVERAGE14 since 2021
inspectionsviolations

HEALTH SAMPLING

Silica and quartz

Matching records00 coal · 0 personal · 0 area
Sample status0 not voided0 voided · 0 status not reported
Personal samples with C/E > 1—0 published ratios · not a citation count
2026 · No reported dates in this selection
Date / sampleDataset / analyteOccupation / areaMeasurementSample statusPublished action
No silica records match these filters. Missing samples do not establish safe conditions.
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.

RECENT PUBLIC RECORDS

Recent violations and samples

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

VIOLATIONS12 latest shown
517795256.14100(c)S&S
517795156.11012Citation
517795056.9300(b)Citation
517794956.12032Citation
517794856.11008Citation
517794756.14112(b)Citation
517794656.11003Citation
517794556.20003(c)S&S
OTHER HEALTH SAMPLES8 latest shown

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

Respirable dust, <.1mgRotary Bucket Ex. Operator
C/E: 00.00Concentration: 0000.00 · limit: 0000.00Source unit unspecified
Respirable dust, <.1mgKiln/Dryer Operator
C/E: 00.00Concentration: 0000.00 · limit: 0000.00Source unit unspecified
Respirable dust, <.1mgUtility Man
C/E: 00.00Concentration: 0000.00 · limit: 0000.00Source unit unspecified
Respirable dust, <.1mgUtility Man
C/E: 00.00Concentration: 0000.00 · limit: 0000.00Source unit unspecified
Respirable dust, <.1mgScale Man
C/E: 00.00Concentration: 0000.00 · limit: 0000.00Source unit unspecified
Respirable dust, <.1mgLaborer, Bullgang
C/E: 00.00Concentration: 0000.00 · limit: 0000.00Source unit unspecified
Respirable dust, <.1mgDry Screen Plant Operator
C/E: 00.00Concentration: 0000.00 · limit: 0000.00Source unit unspecified
Respirable dust, <.1mgTruck Loader
C/E: 00.00Concentration: 0000.00 · limit: 0000.00Source unit unspecified

SOURCE COVERAGE

Reporting dates and coverage

15 datasets contain linked records. Missing datasets are listed below.

DATASETROWSWINDOWSTATUS
Accident, Injuries, and Illnessessafety · contractors34Dec 26, 2000—Aug 10, 2026mine-keyed
Addresses of Recordidentity · logistics1Aug 29, 1975—Aug 29, 1975mine-keyed
Assessed Violationscompliance · legal149Apr 5, 2000—Jul 19, 2026mine-keyed
Civil Penalty Dockets and Decisionscompliance · legal34Dec 18, 2002—Nov 5, 2019mine-keyed
Coal Dust Sampleshealth · safety—No published rowsabsent / not applicable
Conferencescompliance · legal14May 12, 2000—Jun 12, 2018mine-keyed
Contested Violationscompliance · legal32Oct 21, 2004—May 17, 2019mine-keyed
Contractor Employment and Production — Quarterlycontractors · production · safety1,075Not published—Not publishedentity-linked
Contractor Employment and Production — Yearlycontractors · production · safety241Not published—Not publishedentity-linked
Controller and Operator Historyidentity · compliance3Jan 1, 1950—Mar 9, 1996mine-keyed
Mine Employment and Production — Quarterlyproduction · safety · compliance307Not published—Not publishedmine-keyed
Mine Employment and Production — Yearlyproduction · safety · compliance55Not published—Not publishedmine-keyed
Inspectionssafety · compliance78Apr 5, 2000—Jul 13, 2026mine-keyed
Minesidentity · production · logistics1Not published—Not publishedmine-keyed
Metal and Nonmetal Area Sampleshealth · safety—No published rowsabsent / not applicable
Metal and Nonmetal Personal Health Sampleshealth · safety78Aug 27, 2002—Jul 20, 2026mine-keyed
Noise Sampleshealth · safety · equipment—No published rowsabsent / not applicable
Quartz Samples — Coalhealth · safety—No published rowsabsent / not applicable
Violationscompliance · safety · legal154Apr 5, 2000—Jul 19, 2026mine-keyed
107(a) Orders Issuedsafety · compliance—No published rowsabsent / not applicable

NOTES

Limitations

  • Contractor production is entity-level and is never represented as mine-attributable.
  • Missing rows can mean no event, publication delay, identity mismatch, or inapplicability.