# Relationship history for MSHA mine 4002280

Current hierarchy: **Mc Cann Robert L → B S K Mining Company Inc → B S K No 1 Surface**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **controller_controls_mine:** Mc Cann Robert L → B S K No 1 Surface; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** B S K Mining Company Inc → B S K No 1 Surface; 1977-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Mc Cann Robert L → B S K Mining Company Inc; 1977-06-01 to current/open; source msha-controller-operator-history