# Relationship history for MSHA mine 4607756

Current hierarchy: **B W  McDonald → Opportunity Coal Company Inc → Mine No 3**

- 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

- **controller_controls_mine:** Cheyenne Mining Corp → Mine No 3; 1983-05-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Cheyenne Mining Corp → Mine No 3; 1989-09-01 to 1992-08-03; source msha-controller-operator-history
- **controller_controls_operator:** Cheyenne Mining Corp → Cheyenne Mining Corp; 1989-09-01 to 1992-08-03; source msha-controller-operator-history
- **controller_controls_mine:** B W  McDonald → Mine No 3; 1990-02-13 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Opportunity Coal Company Inc → Mine No 3; 1992-08-04 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** B W  McDonald → Opportunity Coal Company Inc; 1992-08-04 to current/open; source msha-controller-operator-history