# Relationship history for MSHA mine 4801099

Current hierarchy: **Union Pacific Corp → Rocky Mountain Energy → Bear Creek**

- 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:** Bear Creek Uranium Company → Bear Creek; 1950-01-01 to 1985-12-31; source msha-controller-operator-history
- **controller_controls_mine:** Rocky Mt Energy Co-Mono Power Co-Halliburton Co → Bear Creek; 1950-01-01 to 1985-12-31; source msha-controller-operator-history
- **controller_controls_operator:** Rocky Mt Energy Co-Mono Power Co-Halliburton Co → Bear Creek Uranium Company; 1950-01-01 to 1985-12-31; source msha-controller-operator-history
- **operator_operates_mine:** Rocky Mountain Energy → Bear Creek; 1986-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Union Pacific Corp → Bear Creek; 1986-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Union Pacific Corp → Rocky Mountain Energy; 1986-01-01 to current/open; source msha-controller-operator-history