# Relationship history for MSHA mine 4604297

Current hierarchy: **Mc Kee Ralph → Wyoming Mining Company Inc → Wyoming No 31 Mine**

- 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

- **controller_controls_mine:** Mc Kee Ralph → Wyoming No 31 Mine; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Wyoming Mining Company Inc → Wyoming No 31 Mine; 1974-08-22 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Mc Kee Ralph → Wyoming Mining Company Inc; 1974-08-22 to current/open; source msha-controller-operator-history