# Relationship history for MSHA mine 1513303

Current hierarchy: **United  Company → Ridgeway Coals Inc → Surface Mine No 4**

- 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:** Ridgeway Coal Inc → Surface Mine No 4; 1981-12-01 to 1986-02-27; source msha-controller-operator-history
- **controller_controls_mine:** Terry Charles  Marshall → Surface Mine No 4; 1981-12-01 to 1988-09-27; source msha-controller-operator-history
- **controller_controls_operator:** Terry Charles  Marshall → Ridgeway Coal Inc; 1981-12-01 to 1986-02-27; source msha-controller-operator-history
- **operator_operates_mine:** Ridgeway Coals Inc → Surface Mine No 4; 1986-02-28 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** United  Company → Surface Mine No 4; 1986-02-28 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** United  Company → Ridgeway Coals Inc; 1986-02-28 to current/open; source msha-controller-operator-history