# Relationship history for MSHA mine 4403253

Current hierarchy: **Excello Coal Corp → Green Hill Mining, Inc. → GHM #35**

- 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:** Wellmore Coal Corp → GHM #35; 1950-01-01 to 1987-09-17; source msha-controller-operator-history
- **controller_controls_mine:** United  Company → GHM #35; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** United  Company → Wellmore Coal Corp; 1950-01-01 to 1987-09-17; source msha-controller-operator-history
- **controller_controls_mine:** Excello Coal Corp → GHM #35; 1975-08-13 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Excello Coal Corp → GHM #35; 1987-09-18 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Excello Coal Corp → Excello Coal Corp; 1987-09-18 to current/open; source msha-controller-operator-history