# Relationship history for MSHA mine 4404463

Current hierarchy: **Mitchell George & Billy → Triple M Coal 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: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **operator_operates_mine:** Big Track Coal Company Inc → No 1 Mine; 1976-05-01 to 1978-09-11; source msha-controller-operator-history
- **controller_controls_mine:** O'Quinn Newton → No 1 Mine; 1976-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** O'Quinn Newton → Big Track Coal Company Inc; 1976-05-01 to 1978-09-11; source msha-controller-operator-history
- **operator_operates_mine:** Triple M Coal Company → No 1 Mine; 1978-09-12 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Mitchell George & Billy Et Al → No 1 Mine; 1978-09-12 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Mitchell George & Billy Et Al → Triple M Coal Company; 1978-09-12 to current/open; source msha-controller-operator-history