# Relationship history for MSHA mine 3606843

Current hierarchy: **Ruff Jean-Paul & Martin Farber → Hawley Fuel Coal Inc → Bullskin 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:** Campbell George R → Bullskin Mine; 1978-05-01 to 1981-12-21; source msha-controller-operator-history
- **operator_operates_mine:** Campbell Coal Company Inc → Bullskin Mine; 1979-05-01 to 1979-11-08; source msha-controller-operator-history
- **controller_controls_operator:** Campbell George R → Campbell Coal Company Inc; 1979-05-01 to 1979-11-08; source msha-controller-operator-history
- **controller_controls_mine:** Albright Barry Et Al → Bullskin Mine; 1979-11-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Southwest Materials Inc → Bullskin Mine; 1979-11-09 to 1983-07-31; source msha-controller-operator-history
- **controller_controls_operator:** Albright Barry Et Al → Southwest Materials Inc; 1979-11-09 to 1983-07-31; source msha-controller-operator-history
- **controller_controls_mine:** Ruff Jean-Paul & Martin Farber → Bullskin Mine; 1983-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Hawley Fuel Coal Inc → Bullskin Mine; 1983-08-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Ruff Jean-Paul & Martin Farber → Hawley Fuel Coal Inc; 1983-08-01 to current/open; source msha-controller-operator-history