# Relationship history for MSHA mine 4002473

Current hierarchy: **Sailors Donald F → Woodcock Coal Company Inc → Woodcock Coal Co Inc-Area No 1**

- 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:** Woodcock Coal Company Inc → Woodcock Coal Co Inc-Area No 1; 1978-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Sailors Donald F → Woodcock Coal Co Inc-Area No 1; 1978-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Sailors Donald F → Woodcock Coal Company Inc; 1978-09-01 to current/open; source msha-controller-operator-history