# Bigfoot Mine

- **MSHA mine ID:** 4105395
- **Status:** Active
- **Type / commodity:** Surface / Construction Sand and Gravel
- **Location:** Atascosa, TX
- **Operator:** Iron Oak Eagle Ford LLC
- **Controller:** Iron Oak Energy Solutions LLC
- **Public source rows linked:** 1,628
- **Source coverage:** 13 / 20
- **Generated:** 2026-10-13T11:26:59.401Z

## Current entity hierarchy

**Iron Oak Energy Solutions LLC (0189021) → Iron Oak Eagle Ford LLC (0159333) → Bigfoot Mine (4105395)**

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

## Controller and operator valid-time history

- **Black Mountain Sand Holdings LLC et al → Iron Oak Eagle Ford LLC:** 2018-11-04 through 2022-06-30; derived from co-tenure at mine 4105395; source `msha-controller-operator-history`.
- **Owl Rock et al → Iron Oak Eagle Ford LLC:** 2018-11-04 through 2022-06-30; derived from co-tenure at mine 4105395; source `msha-controller-operator-history`.
- **Black Mountain Sand Holdings LLC → Iron Oak Eagle Ford LLC:** 2022-07-01 through 2024-10-31; derived from co-tenure at mine 4105395; source `msha-controller-operator-history`.
- **Iron Oak Energy Solutions LLC → Iron Oak Eagle Ford LLC:** 2024-11-01 through current/open; derived from co-tenure at mine 4105395; source `msha-controller-operator-history`.

- History rows: 4
- Typed edges: 8
- 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 — 10 since 2021:** Accidents and injuries 14 historical accident/injury rows; 0 coded fatalities and 407 lost days across the published record.
2. **COMPLIANCE — 65 since 2021:** Violations and penalties 101 violation rows across the full record; 14 carry an S&S flag and $30,147 appears in current assessed amounts.
3. **HEALTH — 15 samples:** Occupational health samples 15 personal. 3 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 42K employee hours and 69 summed average employees across reported subunits in the latest published quarter.
5. **LEGAL — 2 linked rows:** Contests, conferences and decisions 0 contested-violation rows, 0 civil-penalty docket/decision rows, and 2 conference records linked by issuance number.
6. **CONTRACTORS — 5 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 — 24 since 2021:** Inspections 33 inspection events and 625 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 56.14132 — 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 56.5001 — Exposure limits for airborne contaminants.** (1 retained recent row) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-K/part-56/subpart-D/section-56.5001
- **30 CFR 56.14100 — Safety defects; examination, correction and records.** (2 retained recent rows) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-K/part-56/subpart-M/section-56.14100
- **30 CFR 56.18002 — Examination of working places.** (1 retained recent row) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-K/part-56/subpart-Q/section-56.18002
- **30 CFR 56.11012 — Protection for openings around travelways.** (2 retained recent rows) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-K/part-56/subpart-J/section-56.11012
- **30 CFR 56.12008 — Insulation and fittings for power wires and cables.** (1 retained recent row) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-K/part-56/subpart-K/section-56.12008
- **30 CFR 56.4130 — Electric substations and liquid storage facilities.** (1 retained recent row) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-K/part-56/subpart-C/section-56.4130
- **30 CFR 56.14130 — Roll-over protective structures (ROPS) and seat belts.** (1 retained recent row) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-K/part-56/subpart-M/section-56.14130
- **30 CFR 56.4201 — Inspection.** (1 retained recent row) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-K/part-56/subpart-C/section-56.4201
- **30 CFR 56.14112 — Construction and maintenance of guards.** (1 retained recent row) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-K/part-56/subpart-M/section-56.14112

## Source coverage

- **Accident, Injuries, and Illnesses:** 14 rows; 2019-07-16 through 2024-12-28; source ID `msha-accidents`
- **Addresses of Record:** 1 rows; 2018-11-05 through 2018-11-05; source ID `msha-addresses`
- **Assessed Violations:** 99 rows; 2018-11-05 through 2026-04-21; source ID `msha-assessed-violations`
- **Conferences:** 2 rows; 2026-08-20 through 2026-08-20; source ID `msha-conferences`
- **Contractor Employment and Production — Quarterly:** 1,031 rows; unknown through unknown; source ID `msha-contractor-production-quarterly`
- **Contractor Employment and Production — Yearly:** 251 rows; unknown through unknown; source ID `msha-contractor-production-yearly`
- **Controller and Operator History:** 4 rows; 2018-11-04 through 2018-11-04; source ID `msha-controller-operator-history`
- **Inspections:** 33 rows; 2018-11-04 through 2026-09-17; source ID `msha-inspections`
- **Mine Employment and Production — Quarterly:** 60 rows; unknown through unknown; source ID `msha-mine-production-quarterly`
- **Mine Employment and Production — Yearly:** 16 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:** 15 rows; 2021-02-04 through 2026-06-03; source ID `msha-personal-health-samples`
- **Violations:** 101 rows; 2018-11-05 through 2026-09-17; 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/bigfoot-mine-4105395`
- JSON: `/api/v1/mines/bigfoot-mine-4105395`
- Silica records, units, sample status and quarterly means: `/api/v1/mines/4105395/silica` (snapshot year by default; `?year=all` for history; `&format=csv` for all matching rows)
- Relationship JSON: `/api/v1/mines/4105395/relationships`
- MCP resource: `mine://4105395/assessment`
- Complete Title 30 corpus: `/data/title30-sections.json`