# Relationship history for MSHA mine 4002855

Current hierarchy: **Young William E → B & A Coal Company → No 1 Surface Mine**

- 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:** Young William E → No 1 Surface Mine; 1983-09-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** B & A Coal Company → No 1 Surface Mine; 1984-08-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Young William E → B & A Coal Company; 1984-08-01 to current/open; source msha-controller-operator-history