# Relationship history for MSHA mine 1509766

Current hierarchy: **Kentucky & Ohio Coal Production Co Inc → Kentucky & Ohio Coal Production Co Inc → No 1 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:** Tom Cooper Mining Inc → No 1 Surface; 1976-03-09 to 1976-08-30; source msha-controller-operator-history
- **controller_controls_mine:** Mc Elwrath David → No 1 Surface; 1976-03-09 to 1976-08-30; source msha-controller-operator-history
- **controller_controls_operator:** Mc Elwrath David → Tom Cooper Mining Inc; 1976-03-09 to 1976-08-30; source msha-controller-operator-history
- **operator_operates_mine:** Kentucky & Ohio Coal Production Co Inc → No 1 Surface; 1976-08-31 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Kentucky & Ohio Coal Production Co Inc → No 1 Surface; 1976-08-31 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Kentucky & Ohio Coal Production Co Inc → Kentucky & Ohio Coal Production Co Inc; 1976-08-31 to current/open; source msha-controller-operator-history