# Relationship history for MSHA mine 1513547

Current hierarchy: **CONSOL Energy Inc → Sierra Coal Company → Victoria Coal Co Dba Voyager Minin**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-18T09:31:49.615908+00:00

## Valid-time edges

- **operator_operates_mine:** Voyager Mining Company → Victoria Coal Co Dba Voyager Minin; 1982-06-01 to 1984-04-01; source msha-controller-operator-history
- **controller_controls_mine:** General Electric Company → Victoria Coal Co Dba Voyager Minin; 1982-06-01 to 1984-04-01; source msha-controller-operator-history
- **controller_controls_operator:** General Electric Company → Voyager Mining Company; 1982-06-01 to 1984-04-01; source msha-controller-operator-history
- **operator_operates_mine:** Sierra Coal Company → Victoria Coal Co Dba Voyager Minin; 1984-04-02 to 1986-07-30; source msha-controller-operator-history
- **controller_controls_mine:** BHP Billiton → Victoria Coal Co Dba Voyager Minin; 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 → Victoria Coal Co Dba Voyager Minin; 1986-07-31 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** CONSOL Energy Inc → Victoria Coal Co Dba Voyager Minin; 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