MSHA DATABASEMSHA records · 9 contributing sources · snapshot Oct 13, 2026

MINE DETAILS

Plant 11

IntermittentSurfaceConstruction Sand and Gravel
MSHA MINE ID2102550
LOCATIONKoochiching, MN
PUBLIC RECORD97 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

6

1 significant & substantial (S&S)

  1. 2025 Q10
  2. 2025 Q20
  3. 2025 Q33
  4. 2025 Q43
  5. 2026 Q10
  6. 2026 Q20
  7. 2026 Q30
  8. 2026 Q4 *0

Accident records

0

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 Q30
  8. 2026 Q4 *0

Proposed penalties · USD

1,138.00

6 of 6 violations with amounts

  1. 2025 Q1—
  2. 2025 Q2—
  3. 2025 Q3470
  4. 2025 Q4668
  5. 2026 Q1—
  6. 2026 Q2—
  7. 2026 Q3—
  8. 2026 Q4 *—

On-site inspection hours

13.75

3 inspections · 3 with hours

  1. 2025 Q1—
  2. 2025 Q2—
  3. 2025 Q310.00
  4. 2025 Q43.75
  5. 2026 Q1—
  6. 2026 Q2—
  7. 2026 Q3—
  8. 2026 Q4 *—
Quarterly safety data
QuarterViolationsS&SProposed USDAccident recordsFatality recordsInspectionsOn-site hours
2025-Q100—000—
2025-Q200—000—
2025-Q330470.0000210.0
2025-Q431668.000013.8
2026-Q100—000—
2026-Q200—000—
2026-Q300—000—
2026-Q4 *00—000—

Most cited CFR sections

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

Safety activity

  1. inspectionF033EB9

    Regular Safety and Health Inspection · 3.8 on-site hours

  2. violation5115063

    56.14112(a)(1) · $151.00 proposed

  3. violation5115062

    56.14112(a)(1) · S&S · $366.00 proposed

  4. violation5115061

    56.14101(a)(2) · $151.00 proposed

  5. inspectionF017895

    Regular Safety and Health Inspection · 9.5 on-site hours

  6. violation9696161

    46.8(a)(2) · $168.00 proposed

  7. violation9696160

    56.14103(b) · $151.00 proposed

  8. violation9696159

    56.9300(a) · $151.00 proposed

  9. inspectionF01502F

    Special Emphasis Programs · 0.5 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 HIERARCHYMark T Thorson → Mark Rock Products → Plant 11
HISTORY RECORDS26 relationships
INTERVAL CHECKPASScontroller/operator overlap
—

Mark T ThorsoncontrolsMark Rock ProductsoperatesPlant 11

msha-controller-operator-history · controller/operator co-tenure derived on mine 2102550
—

Donald C AshworthcontrolsMark Sand & Gravel CompanyoperatesPlant 11

msha-controller-operator-history · controller/operator co-tenure derived on mine 2102550
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 / SAFETYneutral

Accidents and injuries

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

ACCIDENT + INJURY RECORD0 since 2021
accidentsmine-production-quarterly
02 / COMPLIANCEwatch

Violations and penalties

15 violation rows across the full record; 5 carry an S&S flag and $2,414 appears in current assessed amounts.

ENFORCEMENT ACTIVITY15 since 2021
inspectionsviolationsassessed-violationsorders-107a
03 / HEALTHcontext

Occupational health samples

3 personal. 0 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 EXPOSURE3 samples
personal-health-samples
04 / PRODUCTIONcontext

Quarterly production and employment

0 employee hours and 0 summed average employees across reported subunits in the latest published quarter.

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

Contests, conferences and decisions

0 contested-violation rows, 0 civil-penalty docket/decision rows, and 0 conference records linked by issuance number.

POST-ISSUANCE LIFECYCLE0 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 CONTEXT0 linked entities
contractor-production-quarterlycontractor-production-yearlyaccidentsviolations
07 / INSPECTIONScontext

Inspections

10 inspection events and 113 published inspection hours across the historical record.

OVERSIGHT COVERAGE10 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
511506356.14112(a)(1)Citation
511506256.14112(a)(1)S&S
511506156.14101(a)(2)Citation
969616146.8(a)(2)Order
969616056.14103(b)Citation
969615956.9300(a)Citation
613509856.12028Citation
613509756.14132(a)Citation
OTHER HEALTH SAMPLES2 latest shown

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

Respirable dust, <.1mgFront-end Loader Operator
C/E: 00.00Concentration: 0000.00 · limit: 0000.00Source unit unspecified
Respirable dust, <.1mgFront-end Loader Operator
C/E: 00.00Concentration: 0000.00 · limit: 0000.00Source unit unspecified

SOURCE COVERAGE

Reporting dates and coverage

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

DATASETROWSWINDOWSTATUS
Accident, Injuries, and Illnessessafety · contractors—No published rowsabsent / not applicable
Addresses of Recordidentity · logistics1Jul 15, 2021—Jul 15, 2021mine-keyed
Assessed Violationscompliance · legal15Aug 16, 2022—Oct 14, 2025mine-keyed
Civil Penalty Dockets and Decisionscompliance · legal—No published rowsabsent / not applicable
Coal Dust Sampleshealth · safety—No published rowsabsent / not applicable
Conferencescompliance · legal—No published rowsabsent / not applicable
Contested Violationscompliance · legal—No published rowsabsent / not applicable
Contractor Employment and Production — Quarterlycontractors · production · safety—No published rowsabsent / not applicable
Contractor Employment and Production — Yearlycontractors · production · safety—No published rowsabsent / not applicable
Controller and Operator Historyidentity · compliance2Jan 1, 1950—Jun 1, 2021mine-keyed
Mine Employment and Production — Quarterlyproduction · safety · compliance40Not published—Not publishedmine-keyed
Mine Employment and Production — Yearlyproduction · safety · compliance10Not published—Not publishedmine-keyed
Inspectionssafety · compliance10Sep 1, 2021—Oct 14, 2025mine-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 · safety3Sep 27, 2022—Sep 27, 2022mine-keyed
Noise Sampleshealth · safety · equipment—No published rowsabsent / not applicable
Quartz Samples — Coalhealth · safety—No published rowsabsent / not applicable
Violationscompliance · safety · legal15Aug 16, 2022—Oct 14, 2025mine-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.