# Relationship history for MSHA mine 0101428

Current hierarchy: **Martin Billy → M C & P Coal Co Inc → Pit No 2**

- 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:** Martin Billy → Pit No 2; 1975-08-04 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** M C & P Coal Co Inc → Pit No 2; 1975-11-12 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Martin Billy → M C & P Coal Co Inc; 1975-11-12 to current/open; source msha-controller-operator-history