# Relationship history for MSHA mine 1517454

Current hierarchy: **B W  McDonald → Marine Coal Corp → Mine No 24**

- 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:** B W  McDonald → Mine No 24; 1987-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** TECO Energy Inc → Mine No 24; 1991-12-02 to 2015-09-20; source msha-controller-operator-history
- **operator_operates_mine:** Premier Elkhorn Coal Company → Mine No 24; 1993-09-01 to 1993-11-21; source msha-controller-operator-history
- **controller_controls_operator:** TECO Energy Inc → Premier Elkhorn Coal Company; 1993-09-01 to 1993-11-21; source msha-controller-operator-history
- **operator_operates_mine:** Marine Coal Corp → Mine No 24; 1993-11-22 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** B W  McDonald → Marine Coal Corp; 1993-11-22 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** James H  Booth et al → Mine No 24; 2015-09-21 to 2019-06-15; source msha-controller-operator-history
- **controller_controls_operator:** James H  Booth et al → Premier Elkhorn Coal Company; 2015-09-21 to 1993-11-21; source msha-controller-operator-history
- **controller_controls_mine:** J Mark  Campbell → Mine No 24; 2019-06-16 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** J Mark  Campbell → Premier Elkhorn Coal Company; 2019-06-16 to 1993-11-21; source msha-controller-operator-history