# Relationship history for MSHA mine 1502783

Current hierarchy: **Thomas Ralph → Thomas Mining Company → No 1 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:** A & E Coal Co Inc → No 1 Mine; 1950-01-01 to 1975-10-31; source msha-controller-operator-history
- **controller_controls_mine:** Wright Asa → No 1 Mine; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Wright Asa → A & E Coal Co Inc; 1950-01-01 to 1975-10-31; source msha-controller-operator-history
- **operator_operates_mine:** Thomas Mining Company → No 1 Mine; 1975-11-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Thomas Ralph → No 1 Mine; 1975-11-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Thomas Ralph → Thomas Mining Company; 1975-11-01 to current/open; source msha-controller-operator-history