# Relationship history for MSHA mine 4502169

Current hierarchy: **Cyprus Amax Minerals Company → Amax Inc → Mount Tolman Project**

- 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:** Bear Creek Mining Company → Mount Tolman Project; 1950-01-01 to 1978-12-31; source msha-controller-operator-history
- **controller_controls_mine:** Bear Creek Mining Company → Mount Tolman Project; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Bear Creek Mining Company → Bear Creek Mining Company; 1950-01-01 to 1978-12-31; source msha-controller-operator-history
- **operator_operates_mine:** Amax Inc → Mount Tolman Project; 1979-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Cyprus Amax Minerals Company → Mount Tolman Project; 1979-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Cyprus Amax Minerals Company → Amax Inc; 1979-01-01 to current/open; source msha-controller-operator-history