# Relationship history for MSHA mine 4200096

Current hierarchy: **American Electric Power Company Inc → Price River Coal Company → Price River No 6a 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: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** North American Coal Corp → Price River No 6a Mine; 1950-01-01 to 1973-12-31; source msha-controller-operator-history
- **controller_controls_mine:** NACCO Industries Inc → Price River No 6a Mine; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** NACCO Industries Inc → North American Coal Corp; 1950-01-01 to 1973-12-31; source msha-controller-operator-history
- **operator_operates_mine:** Braztah Corp → Price River No 6a Mine; 1974-01-01 to 1979-12-03; source msha-controller-operator-history
- **controller_controls_mine:** Mc Culloch Oil Corp → Price River No 6a Mine; 1974-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Mc Culloch Oil Corp → Braztah Corp; 1974-01-01 to 1979-12-03; source msha-controller-operator-history
- **operator_operates_mine:** Price River Coal Company → Price River No 6a Mine; 1979-12-04 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** American Electric Power Company Inc → Price River No 6a Mine; 1979-12-04 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** American Electric Power Company Inc → Price River Coal Company; 1979-12-04 to current/open; source msha-controller-operator-history