# Relationship history for MSHA mine 4404139

Current hierarchy: **Sproles R C → P G Coal Corp → No 2 Strip Mine**

- 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:** P G Coal Corp → No 2 Strip Mine; 1975-04-30 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Sproles R C → No 2 Strip Mine; 1975-04-30 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Sproles R C → P G Coal Corp; 1975-04-30 to current/open; source msha-controller-operator-history