# Relationship history for MSHA mine 1516975

Current hierarchy: **Thunderbird Energy Inc → Mesa Coals Inc → Bull Run**

- 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:** First Mississippi Corp → Bull Run; 1983-02-23 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Bull Run Mining Company → Bull Run; 1990-09-01 to 1991-08-19; source msha-controller-operator-history
- **controller_controls_mine:** Miller Douglas P → Bull Run; 1990-09-01 to 1991-08-19; source msha-controller-operator-history
- **controller_controls_operator:** Miller Douglas P → Bull Run Mining Company; 1990-09-01 to 1991-08-19; source msha-controller-operator-history
- **operator_operates_mine:** Mesa Coals Inc → Bull Run; 1991-08-20 to 1992-08-31; source msha-controller-operator-history
- **controller_controls_mine:** Lloyd John M → Bull Run; 1991-08-20 to 1993-10-14; source msha-controller-operator-history
- **controller_controls_operator:** Lloyd John M → Mesa Coals Inc; 1991-08-20 to 1992-08-31; source msha-controller-operator-history
- **operator_operates_mine:** Pyramid Mining Inc → Bull Run; 1992-09-01 to 1993-10-14; source msha-controller-operator-history
- **controller_controls_operator:** First Mississippi Corp → Pyramid Mining Inc; 1992-09-01 to 1993-10-14; source msha-controller-operator-history
- **operator_operates_mine:** Mesa Coals Inc → Bull Run; 1993-10-15 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Thunderbird Energy Inc → Bull Run; 1993-10-15 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Thunderbird Energy Inc → Mesa Coals Inc; 1993-10-15 to current/open; source msha-controller-operator-history