# Relationship history for MSHA mine 0901005

Current hierarchy: **Wren Clyde C → C & E Sand & Gravel → Wrenns Pit**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-18T09:31:49.615908+00:00

## Valid-time edges

- **operator_operates_mine:** C & E Sand & Gravel → Wrenns Pit; 1987-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Wren Clyde C → Wrenns Pit; 1987-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Wren Clyde C → C & E Sand & Gravel; 1987-07-01 to current/open; source msha-controller-operator-history