# Relationship history for MSHA mine 4200624

Current hierarchy: **Roedel Mike & Billy → Roedel Mining → Thornburg Memorial**

- 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:** Whitelock Corp → Thornburg Memorial; 1950-01-01 to 1979-11-30; source msha-controller-operator-history
- **controller_controls_mine:** Whitelock Corp → Thornburg Memorial; 1950-01-01 to 1979-11-30; source msha-controller-operator-history
- **controller_controls_operator:** Whitelock Corp → Whitelock Corp; 1950-01-01 to 1979-11-30; source msha-controller-operator-history
- **controller_controls_mine:** Commonwealth Edison Company → Thornburg Memorial; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Cotter Corp → Thornburg Memorial; 1979-12-01 to 1987-01-25; source msha-controller-operator-history
- **controller_controls_operator:** Commonwealth Edison Company → Cotter Corp; 1979-12-01 to 1987-01-25; source msha-controller-operator-history
- **controller_controls_mine:** Shumway Gary → Thornburg Memorial; 1983-04-25 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** W K Enterprise → Thornburg Memorial; 1987-01-26 to 1987-06-10; source msha-controller-operator-history
- **controller_controls_operator:** Shumway Gary → W K Enterprise; 1987-01-26 to 1987-06-10; source msha-controller-operator-history
- **controller_controls_mine:** Roedel Mike & Billy → Thornburg Memorial; 1987-02-03 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Roedel Mining → Thornburg Memorial; 1987-06-11 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Roedel Mike & Billy → Roedel Mining; 1987-06-11 to current/open; source msha-controller-operator-history