# Relationship history for MSHA mine 3604852

Current hierarchy: **Robert E  Murray → Keystone Coal Mining Company → Urling No 1 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

- **controller_controls_mine:** Rochester & Pittsburgh Coal Company → Urling No 1 Mine; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Keystone Coal Mining Corp → Urling No 1 Mine; 1973-01-01 to 1998-09-21; source msha-controller-operator-history
- **controller_controls_operator:** Rochester & Pittsburgh Coal Company → Keystone Coal Mining Corp; 1973-01-01 to 1998-09-21; source msha-controller-operator-history
- **operator_operates_mine:** Keystone Coal Mining Company → Urling No 1 Mine; 1998-09-22 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** CONSOL Energy Inc → Urling No 1 Mine; 1998-09-22 to 2013-12-04; source msha-controller-operator-history
- **controller_controls_operator:** CONSOL Energy Inc → Keystone Coal Mining Company; 1998-09-22 to 2013-12-04; source msha-controller-operator-history
- **controller_controls_mine:** Robert E  Murray → Urling No 1 Mine; 2013-12-05 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Robert E  Murray → Keystone Coal Mining Company; 2013-12-05 to current/open; source msha-controller-operator-history