# JONESVILLE

- **MSHA mine ID:** 2002932
- **Status:** Intermittent
- **Type / commodity:** Surface / Construction Sand and Gravel
- **Location:** Hillsdale, MI
- **Operator:** Gerken Materials Inc.
- **Controller:** Brent  Gerken; Michael J  Gerken
- **Public source rows linked:** 608
- **Source coverage:** 13 / 20
- **Generated:** 2026-10-13T11:26:59.401Z

## Current entity hierarchy

**Brent  Gerken; Michael J  Gerken (M08470) → Gerken Materials Inc. (0088664) → JONESVILLE (2002932)**

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

## Controller and operator valid-time history

- **Robert C  Sloan → Glacial Products Inc:** 1994-06-01 through 1997-04-30; derived from co-tenure at mine 2002932; source `msha-controller-operator-history`.
- **Sutherland John → Glacial Aggregate Inc:** 1997-05-01 through 2000-01-02; derived from co-tenure at mine 2002932; source `msha-controller-operator-history`.
- **Ronald  MacRitchie  et al → Glacial Sand & Gravel:** 2000-01-03 through 2006-02-28; derived from co-tenure at mine 2002932; source `msha-controller-operator-history`.
- **Donald  MacRitchie  et al → Glacial Sand & Gravel:** 2000-01-03 through 2006-02-28; derived from co-tenure at mine 2002932; source `msha-controller-operator-history`.
- **James P  Sturrus → Glacial Aggregate Inc:** 2002-06-19 through 2000-01-02; derived from co-tenure at mine 2002932; source `msha-controller-operator-history`.
- **Brent  Gerken et al → Glacial Sand & Gravel LLC:** 2006-03-01 through 2018-07-18; derived from co-tenure at mine 2002932; source `msha-controller-operator-history`.
- **Michael J  Gerken et al → Glacial Sand & Gravel LLC:** 2006-03-01 through 2018-07-18; derived from co-tenure at mine 2002932; source `msha-controller-operator-history`.
- **Michael J  Gerken et al → Gerken Materials Inc.:** 2018-07-19 through current/open; derived from co-tenure at mine 2002932; source `msha-controller-operator-history`.
- **Brent  Gerken et al → Gerken Materials Inc.:** 2018-07-19 through current/open; derived from co-tenure at mine 2002932; source `msha-controller-operator-history`.

- History rows: 9
- Typed edges: 20
- Interval anomalies: 1
- 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 5 historical accident/injury rows; 0 coded fatalities and 7 lost days across the published record.
2. **COMPLIANCE — 5 since 2021:** Violations and penalties 54 violation rows across the full record; 19 carry an S&S flag and $11,217 appears in current assessed amounts.
3. **HEALTH — 13 samples:** Occupational health samples 13 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 4K employee hours and 9 summed average employees across reported subunits in the latest published quarter.
5. **LEGAL — 1 linked rows:** Contests, conferences and decisions 0 contested-violation rows, 0 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 — 7 since 2021:** Inspections 38 inspection events and 613 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 56.14205 — Machinery, equipment, and tools.** (1 retained recent row) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-K/part-56/subpart-M/section-56.14205
- **30 CFR 50.30 — Preparation and submission of MSHA Form 7000-2—Quarterly Employment and Coal Production Report.** (1 retained recent row) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-I/part-50/subpart-D/section-50.30
- **30 CFR 56.16005 — Securing gas cylinders.** (1 retained recent row) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-K/part-56/subpart-O/section-56.16005
- **30 CFR 56.12018 — Identification of power switches.** (1 retained recent row) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-K/part-56/subpart-K/section-56.12018
- **30 CFR 56.14132 — Horns and backup alarms.** (1 retained recent row) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-K/part-56/subpart-M/section-56.14132
- **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 56.12004 — Electrical conductors.** (1 retained recent row) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-K/part-56/subpart-K/section-56.12004
- **30 CFR 56.14100 — Safety defects; examination, correction and records.** (1 retained recent row) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-K/part-56/subpart-M/section-56.14100
- **30 CFR 56.12008 — Insulation and fittings for power wires and cables.** (2 retained recent rows) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-K/part-56/subpart-K/section-56.12008
- **30 CFR 56.14101 — Brakes.** (1 retained recent row) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-K/part-56/subpart-M/section-56.14101
- **30 CFR 56.12025 — Grounding circuit enclosures.** (1 retained recent row) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-K/part-56/subpart-K/section-56.12025

## Source coverage

- **Accident, Injuries, and Illnesses:** 5 rows; 2000-02-21 through 2016-05-31; source ID `msha-accidents`
- **Addresses of Record:** 1 rows; 2020-03-31 through 2020-03-31; source ID `msha-addresses`
- **Assessed Violations:** 54 rows; 2000-01-21 through 2025-10-08; source ID `msha-assessed-violations`
- **Conferences:** 1 rows; 2026-02-06 through 2026-02-06; source ID `msha-conferences`
- **Contractor Employment and Production — Quarterly:** 141 rows; unknown through unknown; source ID `msha-contractor-production-quarterly`
- **Contractor Employment and Production — Yearly:** 26 rows; unknown through unknown; source ID `msha-contractor-production-yearly`
- **Controller and Operator History:** 9 rows; 1994-06-01 through 2018-07-19; source ID `msha-controller-operator-history`
- **Inspections:** 38 rows; 2000-01-21 through 2025-10-08; source ID `msha-inspections`
- **Mine Employment and Production — Quarterly:** 211 rows; unknown through unknown; source ID `msha-mine-production-quarterly`
- **Mine Employment and Production — Yearly:** 54 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:** 13 rows; 2001-05-06 through 2023-08-29; source ID `msha-personal-health-samples`
- **Violations:** 54 rows; 2000-01-21 through 2025-10-08; 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/jonesville-2002932`
- JSON: `/api/v1/mines/jonesville-2002932`
- Silica records, units, sample status and quarterly means: `/api/v1/mines/2002932/silica` (snapshot year by default; `?year=all` for history; `&format=csv` for all matching rows)
- Relationship JSON: `/api/v1/mines/2002932/relationships`
- MCP resource: `mine://2002932/assessment`
- Complete Title 30 corpus: `/data/title30-sections.json`