# Relationship history for MSHA mine 1504645

Current hierarchy: **Hamilton J Byron → Hillindale Coal Corp → No 4-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

- **operator_operates_mine:** Marbea Coal Company → No 4-Surface; 1950-01-01 to 1972-04-27; source msha-controller-operator-history
- **controller_controls_mine:** Tschudy Kenneth Et Al → No 4-Surface; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Tschudy Kenneth Et Al → Marbea Coal Company; 1950-01-01 to 1972-04-27; source msha-controller-operator-history
- **controller_controls_mine:** Hamilton J Byron → No 4-Surface; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Colmorson Coal Company → No 4-Surface; 1972-04-28 to 1973-02-28; source msha-controller-operator-history
- **controller_controls_mine:** Colmorson Coal Company → No 4-Surface; 1972-04-28 to 1973-02-28; source msha-controller-operator-history
- **controller_controls_operator:** Colmorson Coal Company → Colmorson Coal Company; 1972-04-28 to 1973-02-28; source msha-controller-operator-history
- **operator_operates_mine:** Hillindale Coal Corp → No 4-Surface; 1973-03-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Hamilton J Byron → Hillindale Coal Corp; 1973-03-01 to current/open; source msha-controller-operator-history