# Relationship history for MSHA mine 4601100

Current hierarchy: **Slusher Paul O → Virginia Mineral Developers → Willis Branch Strip 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

- **operator_operates_mine:** White Ridge Coal Co Inc → Willis Branch Strip Mine; 1950-01-01 to 1971-11-30; source msha-controller-operator-history
- **controller_controls_mine:** T W Oil Inc → Willis Branch Strip Mine; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** T W Oil Inc → White Ridge Coal Co Inc; 1950-01-01 to 1971-11-30; source msha-controller-operator-history
- **operator_operates_mine:** Virginia Mineral Developers → Willis Branch Strip Mine; 1971-12-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Slusher Paul O → Willis Branch Strip Mine; 1971-12-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Slusher Paul O → Virginia Mineral Developers; 1971-12-01 to current/open; source msha-controller-operator-history