# Relationship history for MSHA mine 3609188

Current hierarchy: **Gregory R  Chrin → CHRIN BROTHERS INCORPORATED → ISLAND PARK QUARRY**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** Chrin Brothers Incorporated → ISLAND PARK QUARRY; 2004-01-06 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Charles  Chrin → ISLAND PARK QUARRY; 2004-01-06 to 2018-12-31; source msha-controller-operator-history
- **controller_controls_operator:** Charles  Chrin → Chrin Brothers Incorporated; 2004-01-06 to 2018-12-31; source msha-controller-operator-history
- **controller_controls_mine:** Gregory R  Chrin → ISLAND PARK QUARRY; 2019-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Gregory R  Chrin → Chrin Brothers Incorporated; 2019-01-01 to current/open; source msha-controller-operator-history