# Relationship history for MSHA mine 4200717

Current hierarchy: **Rio Tinto Group → Kennecott Utah Copper Corporation → Utah Concentrator North**

- 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

- **operator_operates_mine:** Kennecott Minerals Company → Utah Concentrator North; 1950-01-01 to 1981-06-03; source msha-controller-operator-history
- **controller_controls_mine:** Kennecott Copper Corp → Utah Concentrator North; 1950-01-01 to 1981-06-03; source msha-controller-operator-history
- **controller_controls_operator:** Kennecott Copper Corp → Kennecott Minerals Company; 1950-01-01 to 1981-06-03; source msha-controller-operator-history
- **operator_operates_mine:** Kennecott Corp → Utah Concentrator North; 1981-06-04 to 1989-06-29; source msha-controller-operator-history
- **controller_controls_mine:** British Petroleum Company PLC → Utah Concentrator North; 1981-06-04 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** British Petroleum Company PLC → Kennecott Corp; 1981-06-04 to 1989-06-29; source msha-controller-operator-history
- **operator_operates_mine:** Kennecott Utah Copper Corporation → Utah Concentrator North; 1989-06-30 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Rio Tinto Group → Utah Concentrator North; 1989-06-30 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Rio Tinto Group → Kennecott Utah Copper Corporation; 1989-06-30 to current/open; source msha-controller-operator-history