# Relationship history for MSHA mine 2400928

Current hierarchy: **Rice Robert A → Intermountain Mineral Engineers Inc → Nancy Lee Mill**

- 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 → Nancy Lee Mill; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Western Silver Development Company → Nancy Lee Mill; 1950-01-01 to 1980-07-16; source msha-controller-operator-history
- **controller_controls_mine:** Elander Jay C → Nancy Lee Mill; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Elander Jay C → Western Silver Development Company; 1950-01-01 to 1980-07-16; source msha-controller-operator-history
- **operator_operates_mine:** Intermountain Mineral Engineers Inc → Nancy Lee Mill; 1980-07-17 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Rice Robert A → Intermountain Mineral Engineers Inc; 1980-07-17 to current/open; source msha-controller-operator-history