# PLANT #20

- **MSHA mine ID:** 4703736
- **Status:** Intermittent
- **Type / commodity:** Surface / Crushed, Broken Limestone NEC
- **Location:** Jefferson, WI
- **Operator:** MICHELS ROAD & STONE, INC
- **Controller:** M10 Inc
- **Public source rows linked:** 214
- **Source coverage:** 14 / 20
- **Generated:** 2026-10-13T11:26:59.401Z

## Current entity hierarchy

**M10 Inc (0165247) → MICHELS ROAD & STONE, INC (0179456) → PLANT #20 (4703736)**

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

## Controller and operator valid-time history

- **Michels Corporation → MICHELS CORPORATION:** 2014-09-30 through 2021-10-31; derived from co-tenure at mine 4703736; source `msha-controller-operator-history`.
- **M10 Inc → MICHELS ROAD & STONE, INC:** 2021-11-01 through current/open; derived from co-tenure at mine 4703736; source `msha-controller-operator-history`.

- History rows: 2
- Typed edges: 6
- 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: 2026-10-13T11:19:05.459773+00:00.

## Assessment signals

1. **SAFETY — 0 since 2021:** Accidents and injuries 0 historical accident/injury rows; 0 coded fatalities and 0 lost days across the published record.
2. **COMPLIANCE — 2 since 2021:** Violations and penalties 5 violation rows across the full record; 1 carry an S&S flag and $468 appears in current assessed amounts.
3. **HEALTH — 4 samples:** Occupational health samples 4 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 2K employee hours and 2 summed average employees across reported subunits in the latest published quarter.
5. **LEGAL — 5 linked rows:** Contests, conferences and decisions 2 contested-violation rows, 2 civil-penalty docket/decision rows, and 1 conference records linked by issuance number.
6. **CONTRACTORS — 1 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 — 6 since 2021:** Inspections 16 inspection events and 145 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 46.5 — New miner training.** (1 retained recent row) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-H/part-46/section-46.5
- **30 CFR 56.6306 — Loading, blasting, and security.** (1 retained recent row) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-K/part-56/subpart-E/section-56.6306
- **30 CFR 50.30 — Preparation and submission of MSHA Form 7000-2—Quarterly Employment and Coal Production Report.** (2 retained recent rows) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-I/part-50/subpart-D/section-50.30
- **30 CFR 56.1000 — Notification of commencement of operations and closing of mines.** (1 retained recent row) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-K/part-56/subpart-A/section-56.1000

## Source coverage

- **Addresses of Record:** 1 rows; 2015-01-28 through 2015-01-28; source ID `msha-addresses`
- **Assessed Violations:** 5 rows; 2014-10-01 through 2024-09-10; source ID `msha-assessed-violations`
- **Civil Penalty Dockets and Decisions:** 2 rows; 2021-01-29 through 2021-12-03; source ID `msha-civil-penalty-dockets-decisions`
- **Conferences:** 1 rows; 2025-02-06 through 2025-02-06; source ID `msha-conferences`
- **Contested Violations:** 2 rows; 2020-08-06 through 2021-03-16; source ID `msha-contested-violations`
- **Contractor Employment and Production — Quarterly:** 66 rows; unknown through unknown; source ID `msha-contractor-production-quarterly`
- **Contractor Employment and Production — Yearly:** 18 rows; unknown through unknown; source ID `msha-contractor-production-yearly`
- **Controller and Operator History:** 2 rows; 2014-09-30 through 2021-11-01; source ID `msha-controller-operator-history`
- **Inspections:** 16 rows; 2014-10-01 through 2026-09-01; source ID `msha-inspections`
- **Mine Employment and Production — Quarterly:** 78 rows; unknown through unknown; source ID `msha-mine-production-quarterly`
- **Mine Employment and Production — Yearly:** 13 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:** 4 rows; 2020-09-22 through 2024-09-11; source ID `msha-personal-health-samples`
- **Violations:** 5 rows; 2014-10-01 through 2024-09-10; 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/plant-20-4703736`
- JSON: `/api/v1/mines/plant-20-4703736`
- Silica records, units, sample status and quarterly means: `/api/v1/mines/4703736/silica` (snapshot year by default; `?year=all` for history; `&format=csv` for all matching rows)
- Relationship JSON: `/api/v1/mines/4703736/relationships`
- MCP resource: `mine://4703736/assessment`
- Complete Title 30 corpus: `/data/title30-sections.json`