# Relationship history for MSHA mine 1700001

Current hierarchy: **CRH PLC → Pike Industries → Westbrook Quarry & Mill**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **operator_operates_mine:** Blue Rock Industries → Westbrook Quarry & Mill; 1950-01-01 to 2006-01-16; source msha-controller-operator-history
- **controller_controls_mine:** James  Hinman → Westbrook Quarry & Mill; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** James  Hinman → Blue Rock Industries; 1950-01-01 to 2006-01-16; source msha-controller-operator-history
- **controller_controls_mine:** CRH PLC → Westbrook Quarry & Mill; 1988-06-02 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Pike Industries → Westbrook Quarry & Mill; 2006-01-17 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** CRH PLC → Pike Industries; 2006-01-17 to current/open; source msha-controller-operator-history