# Relationship history for MSHA mine 4200084

Current hierarchy: **General Exploration Company → Swisher Coal Company → Huntington Canyon No 5 Mine**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-18T09:31:49.615908+00:00

## Valid-time edges

- **operator_operates_mine:** Rigby Coal Inc → Huntington Canyon No 5 Mine; 1950-01-01 to 1973-05-09; source msha-controller-operator-history
- **controller_controls_mine:** Rigby Coal Inc → Huntington Canyon No 5 Mine; 1950-01-01 to 1973-05-09; source msha-controller-operator-history
- **controller_controls_operator:** Rigby Coal Inc → Rigby Coal Inc; 1950-01-01 to 1973-05-09; source msha-controller-operator-history
- **operator_operates_mine:** Intermountain Exploration Company → Huntington Canyon No 5 Mine; 1973-05-10 to 1975-10-04; source msha-controller-operator-history
- **controller_controls_mine:** Wyman Richard V → Huntington Canyon No 5 Mine; 1973-05-10 to 1975-10-04; source msha-controller-operator-history
- **controller_controls_operator:** Wyman Richard V → Intermountain Exploration Company; 1973-05-10 to 1975-10-04; source msha-controller-operator-history
- **controller_controls_mine:** General Exploration Company → Huntington Canyon No 5 Mine; 1975-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Swisher Coal Company → Huntington Canyon No 5 Mine; 1975-10-05 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** General Exploration Company → Swisher Coal Company; 1975-10-05 to current/open; source msha-controller-operator-history