# Riverside Operation

- **MSHA mine ID:** 0404263
- **Status:** Active
- **Type / commodity:** Facility / Ground Silica
- **Location:** Riverside, CA
- **Operator:** Riverside Milling Company, LLC
- **Controller:** P W Gillibrand Company Inc
- **Public source rows linked:** 439
- **Source coverage:** 13 / 20
- **Generated:** 2026-10-13T11:26:59.401Z

## Current entity hierarchy

**P W Gillibrand Company Inc (0192001) → Riverside Milling Company, LLC (0153633) → Riverside Operation (0404263)**

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

## Controller and operator valid-time history

- **Oglebay Norton Company → Premier Silica LLC:** 1978-03-09 through 2008-02-12; derived from co-tenure at mine 0404263; source `msha-controller-operator-history`.
- **Carmeuse Holding SA → Premier Silica LLC:** 2008-02-13 through 2012-04-01; derived from co-tenure at mine 0404263; source `msha-controller-operator-history`.
- **Pioneer Natural Resources USA Incorporated → Premier Silica LLC:** 2012-04-02 through 2017-05-31; derived from co-tenure at mine 0404263; source `msha-controller-operator-history`.
- **Celine L  Gillibrand → Riverside Milling Company, LLC:** 2017-06-01 through 2022-07-05; derived from co-tenure at mine 0404263; source `msha-controller-operator-history`.
- **Celine L Gillibrand Trust → Riverside Milling Company, LLC:** 2022-07-06 through 2024-12-26; derived from co-tenure at mine 0404263; source `msha-controller-operator-history`.
- **P W Gillibrand Company Inc → Riverside Milling Company, LLC:** 2024-12-27 through current/open; derived from co-tenure at mine 0404263; source `msha-controller-operator-history`.

- History rows: 6
- Typed edges: 14
- 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 — 1 since 2021:** Accidents and injuries 3 historical accident/injury rows; 0 coded fatalities and 315 lost days across the published record.
2. **COMPLIANCE — 1 since 2021:** Violations and penalties 31 violation rows across the full record; 9 carry an S&S flag and $4,351 appears in current assessed amounts.
3. **HEALTH — 29 samples:** Occupational health samples 29 personal. 1 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 4 summed average employees across reported subunits in the latest published quarter.
5. **LEGAL — 8 linked rows:** Contests, conferences and decisions 4 contested-violation rows, 4 civil-penalty docket/decision rows, and 0 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 — 13 since 2021:** Inspections 59 inspection events and 787 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 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 56.12032 — Inspection and cover plates.** (1 retained recent row) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-K/part-56/subpart-K/section-56.12032
- **30 CFR 56.12030 — Correction of dangerous conditions.** (1 retained recent row) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-K/part-56/subpart-K/section-56.12030
- **30 CFR 56.20011 — Barricades and warning signs.** (1 retained recent row) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-K/part-56/subpart-S/section-56.20011
- **30 CFR 56.14112 — Construction and maintenance of guards.** (2 retained recent rows) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-K/part-56/subpart-M/section-56.14112
- **30 CFR 56.4402 — Safety can use.** (1 retained recent row) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-K/part-56/subpart-C/section-56.4402
- **30 CFR 56.12026 — Grounding transformer and switchgear enclosures.** (1 retained recent row) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-K/part-56/subpart-K/section-56.12026
- **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 56.12028 — 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 56.12008 — 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 56.14107 — Moving machine parts.** (1 retained recent row) — https://www.ecfr.gov/current/title-30/chapter-I/subchapter-K/part-56/subpart-M/section-56.14107

## Source coverage

- **Accident, Injuries, and Illnesses:** 3 rows; 2011-02-07 through 2026-03-19; source ID `msha-accidents`
- **Addresses of Record:** 1 rows; 1978-07-17 through 1978-07-17; source ID `msha-addresses`
- **Assessed Violations:** 30 rows; 2000-02-23 through 2023-08-30; source ID `msha-assessed-violations`
- **Civil Penalty Dockets and Decisions:** 4 rows; 2008-11-12 through 2008-11-12; source ID `msha-civil-penalty-dockets-decisions`
- **Contested Violations:** 4 rows; 2007-10-17 through 2007-10-17; source ID `msha-contested-violations`
- **Contractor Employment and Production — Quarterly:** 5 rows; unknown through unknown; source ID `msha-contractor-production-quarterly`
- **Controller and Operator History:** 6 rows; 1978-03-09 through 2017-06-01; source ID `msha-controller-operator-history`
- **Inspections:** 59 rows; 2000-02-22 through 2026-04-20; source ID `msha-inspections`
- **Mine Employment and Production — Quarterly:** 212 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:** 29 rows; 2002-01-03 through 2025-11-05; source ID `msha-personal-health-samples`
- **Violations:** 31 rows; 2000-02-23 through 2023-08-30; 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/riverside-operation-0404263`
- JSON: `/api/v1/mines/riverside-operation-0404263`
- Silica records, units, sample status and quarterly means: `/api/v1/mines/0404263/silica` (snapshot year by default; `?year=all` for history; `&format=csv` for all matching rows)
- Relationship JSON: `/api/v1/mines/0404263/relationships`
- MCP resource: `mine://0404263/assessment`
- Complete Title 30 corpus: `/data/title30-sections.json`