# Relationship history for MSHA mine 4000952

Current hierarchy: **Evans Billy P → B & A Coals → B & A Coals**

- 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

- **operator_operates_mine:** Blair Fork Coal Company → B & A Coals; 1950-01-01 to 1977-03-31; source msha-controller-operator-history
- **controller_controls_mine:** Blue Diamond Coal Company → B & A Coals; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Blue Diamond Coal Company → Blair Fork Coal Company; 1950-01-01 to 1977-03-31; source msha-controller-operator-history
- **operator_operates_mine:** Whistle Creek Coal Company Inc → B & A Coals; 1977-04-01 to 1982-10-19; source msha-controller-operator-history
- **controller_controls_mine:** Appleby Edd → B & A Coals; 1977-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Appleby Edd → Whistle Creek Coal Company Inc; 1977-04-01 to 1982-10-19; source msha-controller-operator-history
- **operator_operates_mine:** Bear Coal Company Inc → B & A Coals; 1982-10-20 to 1987-03-09; source msha-controller-operator-history
- **controller_controls_mine:** Marsee Ray → B & A Coals; 1982-10-20 to 1987-03-09; source msha-controller-operator-history
- **controller_controls_operator:** Marsee Ray → Bear Coal Company Inc; 1982-10-20 to 1987-03-09; source msha-controller-operator-history
- **operator_operates_mine:** B & A Coals → B & A Coals; 1987-03-10 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Evans Billy P → B & A Coals; 1987-03-10 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Evans Billy P → B & A Coals; 1987-03-10 to current/open; source msha-controller-operator-history