# Relationship history for MSHA mine 1506775

Current hierarchy: **Bizzack John → B W H Coal Inc → No 2 Surface Strip**

- 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:** Paula Coal Co → No 2 Surface Strip; 1950-01-01 to 1976-02-25; source msha-controller-operator-history
- **controller_controls_mine:** Kentucky King Coal Inc → No 2 Surface Strip; 1950-01-01 to 1976-02-25; source msha-controller-operator-history
- **controller_controls_operator:** Kentucky King Coal Inc → Paula Coal Co; 1950-01-01 to 1976-02-25; source msha-controller-operator-history
- **controller_controls_mine:** Bizzack John → No 2 Surface Strip; 1974-10-18 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** B W H Coal Inc → No 2 Surface Strip; 1976-02-26 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Bizzack John → B W H Coal Inc; 1976-02-26 to current/open; source msha-controller-operator-history