# Relationship history for MSHA mine 4403793

Current hierarchy: **Excello Coal Corp → Excello Coal Corp → Surface Mine No 1**

- 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:** Thompson Robert H → Surface Mine No 1; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Roy & Elizabeth Coal Corp → Surface Mine No 1; 1974-09-01 to 1976-10-21; source msha-controller-operator-history
- **controller_controls_operator:** Thompson Robert H → Roy & Elizabeth Coal Corp; 1974-09-01 to 1976-10-21; source msha-controller-operator-history
- **controller_controls_mine:** Excello Coal Corp → Surface Mine No 1; 1975-08-13 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Excello Coal Corp → Surface Mine No 1; 1976-10-22 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Excello Coal Corp → Excello Coal Corp; 1976-10-22 to current/open; source msha-controller-operator-history