# Relationship history for MSHA mine 4403654

Current hierarchy: **Conner Robert B → Pine Grove Coal Company → No 1**

- 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:** Nimbus Mining Co → No 1; 1974-01-01 to 1976-01-20; source msha-controller-operator-history
- **controller_controls_mine:** Nimbus Mining Co → No 1; 1974-01-01 to 1976-01-20; source msha-controller-operator-history
- **controller_controls_operator:** Nimbus Mining Co → Nimbus Mining Co; 1974-01-01 to 1976-01-20; source msha-controller-operator-history
- **controller_controls_mine:** Layne Earnest → No 1; 1974-10-03 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Pruitt Danny E → No 1; 1975-07-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Robert & Jimmy Coal Co → No 1; 1976-01-21 to 1976-02-25; source msha-controller-operator-history
- **controller_controls_mine:** Burks Robert W & Jimmy Stacey → No 1; 1976-01-21 to 1977-03-10; source msha-controller-operator-history
- **controller_controls_operator:** Burks Robert W & Jimmy Stacey → Robert & Jimmy Coal Co; 1976-01-21 to 1976-02-25; source msha-controller-operator-history
- **operator_operates_mine:** Black Bear Coal Corp → No 1; 1976-02-26 to 1977-06-20; source msha-controller-operator-history
- **controller_controls_operator:** Layne Earnest → Black Bear Coal Corp; 1976-02-26 to 1977-06-20; source msha-controller-operator-history
- **operator_operates_mine:** T & T Coal Company Inc → No 1; 1977-06-21 to 1979-10-07; source msha-controller-operator-history
- **controller_controls_mine:** Taylor Carl H → No 1; 1977-06-21 to 1979-10-07; source msha-controller-operator-history
- **controller_controls_operator:** Taylor Carl H → T & T Coal Company Inc; 1977-06-21 to 1979-10-07; source msha-controller-operator-history
- **operator_operates_mine:** Black Hawk Coal Company Inc → No 1; 1979-10-08 to 1982-09-02; source msha-controller-operator-history
- **controller_controls_operator:** Pruitt Danny E → Black Hawk Coal Company Inc; 1979-10-08 to 1982-09-02; source msha-controller-operator-history
- **operator_operates_mine:** Pine Grove Coal Company → No 1; 1982-09-03 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Conner Robert B → No 1; 1982-09-03 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Conner Robert B → Pine Grove Coal Company; 1982-09-03 to current/open; source msha-controller-operator-history