# Relationship history for MSHA mine 1507035

Current hierarchy: **Hall Harold & Mike → Harold Hall 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: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** Boo Coal Company → No 1 Mine; 1974-01-01 to 1974-08-04; source msha-controller-operator-history
- **controller_controls_mine:** Boo Coal Co → No 1 Mine; 1974-01-01 to 1974-08-04; source msha-controller-operator-history
- **controller_controls_operator:** Boo Coal Co → Boo Coal Company; 1974-01-01 to 1974-08-04; source msha-controller-operator-history
- **operator_operates_mine:** Harold Hall Coal Company → No 1 Mine; 1974-08-05 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Hall Harold & Mike → No 1 Mine; 1974-08-05 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Hall Harold & Mike → Harold Hall Coal Company; 1974-08-05 to current/open; source msha-controller-operator-history