# Relationship history for MSHA mine 1509925

Current hierarchy: **Powell Thomas H → T & N Powell Mining Company Inc → E - C Mine**

- 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:** T & N Powell Mining Company Inc → E - C Mine; 1976-08-12 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Powell Thomas H → E - C Mine; 1976-08-12 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Powell Thomas H → T & N Powell Mining Company Inc; 1976-08-12 to current/open; source msha-controller-operator-history