# Alpine Silica-San Antonio

- **MSHA mine ID:** 4105426
- **Status:** Active
- **Type / commodity:** Surface / Sand, Industrial NEC
- **Location:** Bexar, TX
- **Operator:** Alpine Silica, LLC
- **Controller:** Pro Frac Holding Corp
- **Public source rows linked:** 594
- **Source coverage:** 14 / 20
- **Generated:** 2026-10-17T06:17:15.228Z

## Current entity hierarchy

**Pro Frac Holding Corp (0171280) → Alpine Silica, LLC (0154314) → Alpine Silica-San Antonio (4105426)**

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

## Controller and operator valid-time history

- **David  Welch et al → Monarch Silica, LLC:** 2019-04-25 through 2024-01-31; derived from co-tenure at mine 4105426; source `msha-controller-operator-history`.
- **Paul  Welch et al → Monarch Silica, LLC:** 2019-04-25 through 2024-01-31; derived from co-tenure at mine 4105426; source `msha-controller-operator-history`.
- **Wilks Brothers LLC → Alpine Silica, LLC:** 2024-02-01 through 2022-10-09; derived from co-tenure at mine 4105426; source `msha-controller-operator-history`.
- **Pro Frac Holding Corp → Alpine Silica, LLC:** 2024-02-01 through current/open; derived from co-tenure at mine 4105426; source `msha-controller-operator-history`.

- History rows: 4
- Typed edges: 9
- 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: 2026-10-17T05:35:58.500035+00:00.

## Assessment signals

1. **SAFETY — 14 since 2021:** Accidents and injuries 15 historical accident/injury rows; 1 coded fatalities and 235 lost days across the published record.
2. **COMPLIANCE — 82 since 2021:** Violations and penalties 89 violation rows across the full record; 21 carry an S&S flag and $24,563 appears in current assessed amounts.
3. **HEALTH — 9 samples:** Occupational health samples 9 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 — No published quarter:** Quarterly production and employment The source remains registered, but no mine-keyed quarterly production row was published.
5. **LEGAL — 17 linked rows:** Contests, conferences and decisions 8 contested-violation rows, 8 civil-penalty docket/decision rows, and 1 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 — 22 since 2021:** Inspections 25 inspection events and 583 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 56.18002 — Examination of working places.** (2 retained recent rows) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-K/part-56/subpart-Q/section-56.18002
- **30 CFR 56.15005 — Safety belts and lines.** (1 retained recent row) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-K/part-56/subpart-N/section-56.15005
- **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 56.12005 — Protection of power conductors from mobile equipment.** (1 retained recent row) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-K/part-56/subpart-K/section-56.12005
- **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
- **30 CFR 56.14206 — Securing movable parts.** (1 retained recent row) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-K/part-56/subpart-M/section-56.14206
- **30 CFR 56.14207 — Parking procedures for unattended equipment.** (1 retained recent row) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-K/part-56/subpart-M/section-56.14207
- **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 56.11001 — Safe access.** (1 retained recent row) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-K/part-56/subpart-J/section-56.11001
- **30 CFR 50.20 — Preparation and submission of MSHA Report Form 7000-1—Mine Accident, Injury, and Illness Report.** (1 retained recent row) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-I/part-50/subpart-C/section-50.20

## Source coverage

- **Accident, Injuries, and Illnesses:** 15 rows; 2019-05-31 through 2026-03-28; source ID `msha-accidents`
- **Addresses of Record:** 1 rows; 2019-10-01 through 2019-10-01; source ID `msha-addresses`
- **Assessed Violations:** 74 rows; 2020-01-27 through 2026-05-27; source ID `msha-assessed-violations`
- **Civil Penalty Dockets and Decisions:** 8 rows; 2021-12-09 through 2021-12-09; source ID `msha-civil-penalty-dockets-decisions`
- **Conferences:** 1 rows; 2022-02-16 through 2022-02-16; source ID `msha-conferences`
- **Contested Violations:** 8 rows; 2021-03-16 through 2026-05-27; source ID `msha-contested-violations`
- **Contractor Employment and Production — Quarterly:** 278 rows; unknown through unknown; source ID `msha-contractor-production-quarterly`
- **Contractor Employment and Production — Yearly:** 67 rows; unknown through unknown; source ID `msha-contractor-production-yearly`
- **Controller and Operator History:** 4 rows; 2019-04-25 through 2024-02-01; source ID `msha-controller-operator-history`
- **Inspections:** 25 rows; 2019-04-29 through 2026-10-13; source ID `msha-inspections`
- **Mine Employment and Production — Yearly:** 14 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:** 9 rows; 2020-01-29 through 2025-11-14; source ID `msha-personal-health-samples`
- **Violations:** 89 rows; 2020-01-27 through 2026-10-05; 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/alpine-silica-san-antonio-4105426`
- JSON: `/api/v1/mines/alpine-silica-san-antonio-4105426`
- Silica records, units, sample status and quarterly means: `/api/v1/mines/4105426/silica` (snapshot year by default; `?year=all` for history; `&format=csv` for all matching rows)
- Relationship JSON: `/api/v1/mines/4105426/relationships`
- MCP resource: `mine://4105426/assessment`
- Complete Title 30 corpus: `/data/title30-sections.json`