# Relationship history for MSHA mine 1517732

Current hierarchy: **Noel E  Hardwick → Frontier Mining Company Inc → Panther Creek 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:** Sisk John S & Gerlie V Rickard → Panther Creek Mine; 1995-08-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Ken-Coal Inc → Panther Creek Mine; 1995-11-01 to 2000-06-04; source msha-controller-operator-history
- **controller_controls_operator:** Sisk John S & Gerlie V Rickard → Ken-Coal Inc; 1995-11-01 to 2000-06-04; source msha-controller-operator-history
- **operator_operates_mine:** Frontier Mining Company Inc → Panther Creek Mine; 2000-06-05 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Noel E  Hardwick → Panther Creek Mine; 2000-06-05 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Noel E  Hardwick → Frontier Mining Company Inc; 2000-06-05 to current/open; source msha-controller-operator-history