# O-N Minerals, Cedarville Operation

- **MSHA mine ID:** 2000061
- **Status:** Active
- **Type / commodity:** Surface / Crushed, Broken Limestone NEC
- **Location:** Mackinac, MI
- **Operator:** O-N Minerals (Michigan) Company
- **Controller:** Carmeuse Holding SA
- **Public source rows linked:** 5,731
- **Source coverage:** 15 / 20
- **Generated:** 2026-10-17T06:17:15.228Z

## Current entity hierarchy

**Carmeuse Holding SA (M10266) → O-N Minerals (Michigan) Company (L17341) → O-N Minerals, Cedarville Operation (2000061)**

Current identity source: `msha-mines`. This is a current snapshot, not a historical claim.

## Controller and operator valid-time history

- **USX Corp (United States Steel Corp) → Usx Corp:** 1950-01-01 through 1987-09-21; derived from co-tenure at mine 2000061; source `msha-controller-operator-history`.
- **Michigan Mnrls Associates Inc  et al → Michigan Limestone Operations-Ltd Partnership:** 1987-09-22 through 2000-04-17; derived from co-tenure at mine 2000061; source `msha-controller-operator-history`.
- **Oglebay Norton Company → O-N Minerals (Michigan) Company:** 2000-04-18 through 2008-02-12; derived from co-tenure at mine 2000061; source `msha-controller-operator-history`.
- **Carmeuse Holding SA → O-N Minerals (Michigan) Company:** 2008-02-13 through current/open; derived from co-tenure at mine 2000061; source `msha-controller-operator-history`.

- History rows: 4
- Typed edges: 11
- Interval anomalies: 0
- Valid-time bounds: inclusive; date granularity; null end means open-ended in the upstream history row; not independent proof of present control.
- Transaction-time observation: 2026-10-17T05:35:58.500035+00:00.

## Assessment signals

1. **SAFETY — 10 since 2021:** Accidents and injuries 94 historical accident/injury rows; 1 coded fatalities and 1,674 lost days across the published record.
2. **COMPLIANCE — 156 since 2021:** Violations and penalties 845 violation rows across the full record; 166 carry an S&S flag and $392,220 appears in current assessed amounts.
3. **HEALTH — 116 samples:** Occupational health samples 116 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.
4. **PRODUCTION — 0 tons:** Quarterly production and employment 44K employee hours and 76 summed average employees across reported subunits in the latest published quarter.
5. **LEGAL — 60 linked rows:** Contests, conferences and decisions 15 contested-violation rows, 19 civil-penalty docket/decision rows, and 26 conference records linked by issuance number.
6. **CONTRACTORS — 28 linked entities:** 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.
7. **INSPECTIONS — 38 since 2021:** Inspections 131 inspection events and 6K published inspection hours across the historical record.

## EIA annual operating context

No matched record in the 2024 EIA coal-public workbook. This may be inapplicable for a non-coal operation.

## Recent Title 30 crosswalk

Snapshot current through 2026-08-19.

- **30 CFR 56.4101 — Warning signs.** (1 retained recent row) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-K/part-56/subpart-C/section-56.4101
- **30 CFR 56.4603 — Closure of valves.** (1 retained recent row) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-K/part-56/subpart-C/section-56.4603
- **30 CFR 56.9300 — Berms or guardrails.** (1 retained recent row) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-K/part-56/subpart-H/section-56.9300
- **30 CFR 56.4201 — Inspection.** (3 retained recent rows) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-K/part-56/subpart-C/section-56.4201
- **30 CFR 56.12018 — Identification of power switches.** (2 retained recent rows) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-K/part-56/subpart-K/section-56.12018
- **30 CFR 56.20003 — Housekeeping.** (1 retained recent row) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-K/part-56/subpart-S/section-56.20003
- **30 CFR 56.4601 — Oxygen cylinder storage.** (1 retained recent row) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-K/part-56/subpart-C/section-56.4601
- **30 CFR 56.12028 — Testing grounding systems.** (1 retained recent row) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-K/part-56/subpart-K/section-56.12028
- **30 CFR 46.9 — Records of training.** (1 retained recent row) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-H/part-46/section-46.9

## Source coverage

- **Accident, Injuries, and Illnesses:** 94 rows; 2000-04-20 through 2026-04-07; source ID `msha-accidents`
- **Addresses of Record:** 1 rows; 1991-04-09 through 1991-04-09; source ID `msha-addresses`
- **Assessed Violations:** 834 rows; 2000-04-18 through 2026-06-05; source ID `msha-assessed-violations`
- **Civil Penalty Dockets and Decisions:** 19 rows; 2001-04-30 through 2026-06-24; source ID `msha-civil-penalty-dockets-decisions`
- **Conferences:** 26 rows; 2004-02-03 through 2026-09-17; source ID `msha-conferences`
- **Contested Violations:** 15 rows; 2012-08-28 through 2026-03-11; source ID `msha-contested-violations`
- **Contractor Employment and Production — Quarterly:** 2,892 rows; unknown through unknown; source ID `msha-contractor-production-quarterly`
- **Contractor Employment and Production — Yearly:** 636 rows; unknown through unknown; source ID `msha-contractor-production-yearly`
- **Controller and Operator History:** 4 rows; 1950-01-01 through 2000-04-18; source ID `msha-controller-operator-history`
- **Inspections:** 131 rows; 2000-01-20 through 2026-09-02; source ID `msha-inspections`
- **Mine Employment and Production — Quarterly:** 36 rows; unknown through unknown; source ID `msha-mine-production-quarterly`
- **Mine Employment and Production — Yearly:** 81 rows; unknown through unknown; source ID `msha-mine-production-yearly`
- **Mines:** 1 rows; unknown through unknown; source ID `msha-mines`
- **Metal and Nonmetal Personal Health Samples:** 116 rows; 2004-05-04 through 2026-06-04; source ID `msha-personal-health-samples`
- **Violations:** 845 rows; 2000-04-18 through 2026-06-05; source ID `msha-violations`

## Caveats

- This is public-record decision support, not legal advice or an official MSHA record.
- Missing data can indicate no event, publication delay, an unresolved identity, or inapplicability.
- Contractor production data is entity-level and is not attributed to this mine.

## Alternate representations

- HTML: `/mines/o-n-minerals-cedarville-operation-2000061`
- JSON: `/api/v1/mines/o-n-minerals-cedarville-operation-2000061`
- Silica records, units, sample status and quarterly means: `/api/v1/mines/2000061/silica` (snapshot year by default; `?year=all` for history; `&format=csv` for all matching rows)
- Relationship JSON: `/api/v1/mines/2000061/relationships`
- MCP resource: `mine://2000061/assessment`
- Complete Title 30 corpus: `/data/title30-sections.json`