# Relationship history for MSHA mine 1001458

Current hierarchy: **Alta Gold Company → Alta Gold Company → Copper Cliff 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:** Silver King Mines Inc → Copper Cliff Mill; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Silver King Mines Inc → Copper Cliff Mill; 1980-03-01 to 1987-10-12; source msha-controller-operator-history
- **controller_controls_operator:** Silver King Mines Inc → Silver King Mines Inc; 1980-03-01 to 1987-10-12; source msha-controller-operator-history
- **controller_controls_mine:** Alta Gold Company → Copper Cliff Mill; 1985-04-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Alta Gold Company → Copper Cliff Mill; 1987-10-13 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Alta Gold Company → Alta Gold Company; 1987-10-13 to current/open; source msha-controller-operator-history