# Relationship history for MSHA mine 4605801

Current hierarchy: **Toney David H → Bear Run Coals Inc → No 21 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

- **controller_controls_mine:** Wheeling-Pittsburgh Corp → No 21 Mine; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** W-P Coal Company → No 21 Mine; 1978-06-01 to 1988-02-09; source msha-controller-operator-history
- **controller_controls_operator:** Wheeling-Pittsburgh Corp → W-P Coal Company; 1978-06-01 to 1988-02-09; source msha-controller-operator-history
- **operator_operates_mine:** Deer Run Mining Inc → No 21 Mine; 1988-02-10 to 1989-12-10; source msha-controller-operator-history
- **controller_controls_mine:** Herndon David N → No 21 Mine; 1988-02-10 to 1989-12-10; source msha-controller-operator-history
- **controller_controls_operator:** Herndon David N → Deer Run Mining Inc; 1988-02-10 to 1989-12-10; source msha-controller-operator-history
- **controller_controls_mine:** Adkins William Mitchell → No 21 Mine; 1989-10-03 to 1991-10-10; source msha-controller-operator-history
- **operator_operates_mine:** Top Kat Mining Inc → No 21 Mine; 1989-12-11 to 1991-10-10; source msha-controller-operator-history
- **controller_controls_operator:** Adkins William Mitchell → Top Kat Mining Inc; 1989-12-11 to 1991-10-10; source msha-controller-operator-history
- **operator_operates_mine:** Bear Run Coals Inc → No 21 Mine; 1991-10-11 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Toney David H → No 21 Mine; 1991-10-11 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Toney David H → Bear Run Coals Inc; 1991-10-11 to current/open; source msha-controller-operator-history