# Relationship history for MSHA mine 1500584

Current hierarchy: **Turner Herbert Coal Company → Herbert Turner 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:** Coals Inc → No 1 Mine; 1950-01-01 to 1971-05-31; source msha-controller-operator-history
- **controller_controls_mine:** Sergent Ben → No 1 Mine; 1950-01-01 to 1971-05-31; source msha-controller-operator-history
- **controller_controls_operator:** Sergent Ben → Coals Inc; 1950-01-01 to 1971-05-31; source msha-controller-operator-history
- **operator_operates_mine:** Herbert Turner Coal Company → No 1 Mine; 1971-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Turner Herbert Coal Company → No 1 Mine; 1971-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Turner Herbert Coal Company → Herbert Turner Coal Company; 1971-06-01 to current/open; source msha-controller-operator-history