# Relationship history for MSHA mine 1001636

Current hierarchy: **Rice Robert A → Intermountain Mineral Engineers Inc → Crescent Lease**

- 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

- **controller_controls_mine:** Rice Robert A → Crescent Lease; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Intermountain Mineral Engineers Inc → Crescent Lease; 1984-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Rice Robert A → Intermountain Mineral Engineers Inc; 1984-05-01 to current/open; source msha-controller-operator-history