# Relationship history for MSHA mine 4608720

Current hierarchy: **Brent M  Cook → Covol Technologies Inc → Mountaineer Synfuel**

- 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:** Brent M  Cook → Mountaineer Synfuel; 1997-06-25 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** P T Mine Services Inc → Mountaineer Synfuel; 1998-06-01 to 1998-11-30; source msha-controller-operator-history
- **controller_controls_mine:** Tenney Paul D Ii → Mountaineer Synfuel; 1998-06-01 to 1998-11-30; source msha-controller-operator-history
- **controller_controls_operator:** Tenney Paul D Ii → P T Mine Services Inc; 1998-06-01 to 1998-11-30; source msha-controller-operator-history
- **operator_operates_mine:** Covol Technologies Inc → Mountaineer Synfuel; 1998-12-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Brent M  Cook → Covol Technologies Inc; 1998-12-01 to current/open; source msha-controller-operator-history