# Relationship history for MSHA mine 1517620

Current hierarchy: **Centennial Coal Inc → Centennial Resources Inc → Walton 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: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **controller_controls_mine:** Thunderbird Energy Inc → Walton Creek Mine; 1993-10-15 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Bill  Carver → Walton Creek Mine; 1993-11-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Mesa Coals Inc → Walton Creek Mine; 1994-11-01 to 1995-01-09; source msha-controller-operator-history
- **controller_controls_operator:** Thunderbird Energy Inc → Mesa Coals Inc; 1994-11-01 to 1995-01-09; source msha-controller-operator-history
- **operator_operates_mine:** Progressive Mining Inc → Walton Creek Mine; 1995-01-10 to 1997-03-15; source msha-controller-operator-history
- **controller_controls_operator:** Bill  Carver → Progressive Mining Inc; 1995-01-10 to 1997-03-15; source msha-controller-operator-history
- **controller_controls_mine:** Centennial Coal Inc → Walton Creek Mine; 1997-03-07 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Centennial Resources Inc → Walton Creek Mine; 1997-03-16 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Centennial Coal Inc → Centennial Resources Inc; 1997-03-16 to current/open; source msha-controller-operator-history