# Relationship history for MSHA mine 4607763

Current hierarchy: **Turner William C → T & T Coal Auger Inc → Webster Auger**

- 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

- **operator_operates_mine:** T & T Coal Auger Inc → Webster Auger; 1989-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Turner William C → Webster Auger; 1989-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Turner William C → T & T Coal Auger Inc; 1989-09-01 to current/open; source msha-controller-operator-history