# Relationship history for MSHA mine 4201715

Current hierarchy: **Robert E  Murray → Genwal Resources Inc → Crandall Canyon 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: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **operator_operates_mine:** Genwal Coal Company Inc → Crandall Canyon Mine; 1981-01-01 to 1988-12-31; source msha-controller-operator-history
- **controller_controls_mine:** Charles H  Gent → Crandall Canyon Mine; 1981-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Charles H  Gent → Genwal Coal Company Inc; 1981-01-01 to 1988-12-31; source msha-controller-operator-history
- **operator_operates_mine:** Genwal Coal Company Inc → Crandall Canyon Mine; 1989-01-01 to 1995-01-11; source msha-controller-operator-history
- **controller_controls_mine:** NV Energy dba Nevada Power Company → Crandall Canyon Mine; 1989-01-01 to 1995-01-11; source msha-controller-operator-history
- **controller_controls_operator:** NV Energy dba Nevada Power Company → Genwal Coal Company Inc; 1989-01-01 to 1995-01-11; source msha-controller-operator-history
- **operator_operates_mine:** Genwal Resources Inc → Crandall Canyon Mine; 1995-01-12 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Andalex Resources B V → Crandall Canyon Mine; 1995-01-12 to 2006-08-08; source msha-controller-operator-history
- **controller_controls_operator:** Andalex Resources B V → Genwal Resources Inc; 1995-01-12 to 2006-08-08; source msha-controller-operator-history
- **controller_controls_mine:** Robert E  Murray → Crandall Canyon Mine; 2006-08-09 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Robert E  Murray → Genwal Resources Inc; 2006-08-09 to current/open; source msha-controller-operator-history