# Relationship history for MSHA mine 1505080

Current hierarchy: **Tesoro Petroleum → Tesoro Coal Company → No 1 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:** Buckhorn Hazard Coal Corp → No 1 Mine; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Allegheny Energy Corp → No 1 Mine; 1950-01-01 to 1973-03-01; source msha-controller-operator-history
- **controller_controls_mine:** Allegheny Energy Corp → No 1 Mine; 1950-01-01 to 1973-03-01; source msha-controller-operator-history
- **controller_controls_operator:** Allegheny Energy Corp → Allegheny Energy Corp; 1950-01-01 to 1973-03-01; source msha-controller-operator-history
- **operator_operates_mine:** Buckhorn Hazard Coal Corp → No 1 Mine; 1973-03-02 to 1975-01-30; source msha-controller-operator-history
- **controller_controls_operator:** Buckhorn Hazard Coal Corp → Buckhorn Hazard Coal Corp; 1973-03-02 to 1975-01-30; source msha-controller-operator-history
- **controller_controls_mine:** Tesoro Petroleum → No 1 Mine; 1975-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Tesoro Coal Company → No 1 Mine; 1975-01-31 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Tesoro Petroleum → Tesoro Coal Company; 1975-01-31 to current/open; source msha-controller-operator-history