# Relationship history for MSHA mine 3610439

Current hierarchy: **Brian R  Blair → B. Blair Corporation → B. Blair Crusher 01 Sandvic QJ341**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-18T09:31:49.615908+00:00

## Valid-time edges

- **operator_operates_mine:** B. Blair Corporation → B. Blair Crusher 01 Sandvic QJ341; 2024-01-15 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Brian R  Blair → B. Blair Crusher 01 Sandvic QJ341; 2024-01-15 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Brian R  Blair → B. Blair Corporation; 2024-01-15 to current/open; source msha-controller-operator-history