# Relationship history for MSHA mine 1507125

Current hierarchy: **Johnson R B → Alma Coal Corp → Pikeville No 1 Dock**

- 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:** Peter Fork Mining Company → Pikeville No 1 Dock; 1974-01-01 to 1977-01-16; source msha-controller-operator-history
- **controller_controls_mine:** Robert C  Billips → Pikeville No 1 Dock; 1974-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Robert C  Billips → Peter Fork Mining Company; 1974-01-01 to 1977-01-16; source msha-controller-operator-history
- **controller_controls_mine:** Johnson R B → Pikeville No 1 Dock; 1976-12-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Alma Coal Corp → Pikeville No 1 Dock; 1977-01-17 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Johnson R B → Alma Coal Corp; 1977-01-17 to current/open; source msha-controller-operator-history