# Relationship history for MSHA mine 4201590

Current hierarchy: **Sunoco, Inc. → Sunedco Coal Company → Rock Canyon East 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: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** Eureka Energy Company → Rock Canyon East Mine; 1979-04-01 to 1982-06-20; source msha-controller-operator-history
- **controller_controls_mine:** U S Operating Services Holdings Inc → Rock Canyon East Mine; 1979-04-01 to 1982-06-20; source msha-controller-operator-history
- **controller_controls_operator:** U S Operating Services Holdings Inc → Eureka Energy Company; 1979-04-01 to 1982-06-20; source msha-controller-operator-history
- **controller_controls_mine:** Sunoco, Inc. → Rock Canyon East Mine; 1982-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Sunedco Coal Company → Rock Canyon East Mine; 1982-06-21 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Sunoco, Inc. → Sunedco Coal Company; 1982-06-21 to current/open; source msha-controller-operator-history