# Relationship history for MSHA mine 1507771

Current hierarchy: **Walsh Eugene & William J Morse → Rough River Coal Company Inc → Mine No 4**

- 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

- **operator_operates_mine:** Rough River Coal Company Inc → Mine No 4; 1974-11-05 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Walsh Eugene & William J Morse → Mine No 4; 1974-11-05 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Walsh Eugene & William J Morse → Rough River Coal Company Inc; 1974-11-05 to current/open; source msha-controller-operator-history