# Relationship history for MSHA mine 4605448

Current hierarchy: **Westmoreland Coal Company → Westmoreland Coal Company → No 1 Surface**

- 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:** Westmoreland Coal Company → No 1 Surface; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Bowen Trucking Company → No 1 Surface; 1977-03-01 to 1979-12-10; source msha-controller-operator-history
- **controller_controls_mine:** Bowen Max & Roger Milam → No 1 Surface; 1977-03-01 to 1979-12-10; source msha-controller-operator-history
- **controller_controls_operator:** Bowen Max & Roger Milam → Bowen Trucking Company; 1977-03-01 to 1979-12-10; source msha-controller-operator-history
- **operator_operates_mine:** Westmoreland Coal Company → No 1 Surface; 1979-12-11 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Westmoreland Coal Company → Westmoreland Coal Company; 1979-12-11 to current/open; source msha-controller-operator-history