# Relationship history for MSHA mine 2200721

Current hierarchy: **CRH PLC → Blain Sand & Gravel Inc → THAMES**

- 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

- **controller_controls_mine:** Blain Sand & Gravel Inc → THAMES; 1950-01-01 to 2021-12-02; source msha-controller-operator-history
- **operator_operates_mine:** Blain Sand & Gravel Inc → THAMES; 1999-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Blain Sand & Gravel Inc → Blain Sand & Gravel Inc; 1999-10-01 to 2021-12-02; source msha-controller-operator-history
- **controller_controls_mine:** CRH PLC → THAMES; 2021-12-03 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** CRH PLC → Blain Sand & Gravel Inc; 2021-12-03 to current/open; source msha-controller-operator-history