# Relationship history for MSHA mine 0101461

Current hierarchy: **Otis R  Robison Jr → Robison Mining Company → Margaret 59-1 Strip**

- 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

- **operator_operates_mine:** Robison Mining Company → Margaret 59-1 Strip; 1976-02-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Otis R  Robison Jr → Margaret 59-1 Strip; 1976-02-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Otis R  Robison Jr → Robison Mining Company; 1976-02-01 to current/open; source msha-controller-operator-history