# Relationship history for MSHA mine 3303300

Current hierarchy: **Boich Wayne → W B Coal Company → Ann Strip No 1**

- 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:** Boich Wayne → Ann Strip No 1; 1974-10-21 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** W B Coal Company → Ann Strip No 1; 1975-04-18 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Boich Wayne → W B Coal Company; 1975-04-18 to current/open; source msha-controller-operator-history