# Relationship history for MSHA mine 3608540

Current hierarchy: **Robert E  Murray → Murray Keystone Processing, Inc. → Keystone Cleaning Plant**

- 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

- **controller_controls_mine:** Rochester & Pittsburgh Coal Company → Keystone Cleaning Plant; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Keystone Coal Mining Corp → Keystone Cleaning Plant; 1996-01-01 to 1998-09-21; source msha-controller-operator-history
- **controller_controls_operator:** Rochester & Pittsburgh Coal Company → Keystone Coal Mining Corp; 1996-01-01 to 1998-09-21; source msha-controller-operator-history
- **operator_operates_mine:** Keystone Coal Mining Corporation → Keystone Cleaning Plant; 1998-09-22 to 2016-12-11; source msha-controller-operator-history
- **controller_controls_mine:** CONSOL Energy Inc → Keystone Cleaning Plant; 1998-09-22 to 2013-12-04; source msha-controller-operator-history
- **controller_controls_operator:** CONSOL Energy Inc → Keystone Coal Mining Corporation; 1998-09-22 to 2013-12-04; source msha-controller-operator-history
- **controller_controls_mine:** Robert E  Murray → Keystone Cleaning Plant; 2013-12-05 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Robert E  Murray → Keystone Coal Mining Corporation; 2013-12-05 to 2016-12-11; source msha-controller-operator-history
- **operator_operates_mine:** Murray Keystone Processing, Inc. → Keystone Cleaning Plant; 2016-12-12 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Robert E  Murray → Keystone Cleaning Plant; 2016-12-12 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Robert E  Murray → Murray Keystone Processing, Inc.; 2016-12-12 to current/open; source msha-controller-operator-history