# Relationship history for MSHA mine 1505486

Current hierarchy: **CONSOL Energy Inc → Sierra Coal Company → Redwood Coal Co Loadout Facility**

- 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:** Marty Corp → Redwood Coal Co Loadout Facility; 1950-01-01 to 1981-04-30; source msha-controller-operator-history
- **controller_controls_mine:** Large Russell O → Redwood Coal Co Loadout Facility; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Large Russell O → Marty Corp; 1950-01-01 to 1981-04-30; source msha-controller-operator-history
- **operator_operates_mine:** Redwood Coal Company Inc → Redwood Coal Co Loadout Facility; 1981-05-01 to 1984-04-01; source msha-controller-operator-history
- **controller_controls_mine:** General Electric Company → Redwood Coal Co Loadout Facility; 1981-05-01 to 1984-04-01; source msha-controller-operator-history
- **controller_controls_operator:** General Electric Company → Redwood Coal Company Inc; 1981-05-01 to 1984-04-01; source msha-controller-operator-history
- **operator_operates_mine:** Sierra Coal Company → Redwood Coal Co Loadout Facility; 1984-04-02 to 1986-07-30; source msha-controller-operator-history
- **controller_controls_mine:** BHP Billiton → Redwood Coal Co Loadout Facility; 1984-04-02 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** BHP Billiton → Sierra Coal Company; 1984-04-02 to 1986-07-30; source msha-controller-operator-history
- **operator_operates_mine:** Sierra Coal Company → Redwood Coal Co Loadout Facility; 1986-07-31 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** CONSOL Energy Inc → Redwood Coal Co Loadout Facility; 1986-07-31 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** CONSOL Energy Inc → Sierra Coal Company; 1986-07-31 to current/open; source msha-controller-operator-history