# Relationship history for MSHA mine 4604303

Current hierarchy: **T W Oil Inc → White Ridge Coal Co Inc → Freezeland Surface**

- 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:** T W Oil Inc → Freezeland Surface; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Winkelman Dwight W → Freezeland Surface; 1974-06-04 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** D W Winkelman Company → Freezeland Surface; 1974-09-09 to 1975-12-02; source msha-controller-operator-history
- **controller_controls_operator:** Winkelman Dwight W → D W Winkelman Company; 1974-09-09 to 1975-12-02; source msha-controller-operator-history
- **operator_operates_mine:** White Ridge Coal Co Inc → Freezeland Surface; 1975-12-03 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** T W Oil Inc → White Ridge Coal Co Inc; 1975-12-03 to current/open; source msha-controller-operator-history