# Relationship history for MSHA mine 1507762

Current hierarchy: **Ratliff James Delbert-Danny L & Donald E → Regina Fuel Company → No 4 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

- **controller_controls_mine:** Ratliff James Delbert-Danny L & Donald E → No 4 Mine; 1974-07-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Blackburn & Ratliff Coal Company → No 4 Mine; 1974-12-06 to 1975-02-18; source msha-controller-operator-history
- **controller_controls_mine:** Blackburn James & George R Ratliff → No 4 Mine; 1974-12-06 to 1975-02-18; source msha-controller-operator-history
- **controller_controls_operator:** Blackburn James & George R Ratliff → Blackburn & Ratliff Coal Company; 1974-12-06 to 1975-02-18; source msha-controller-operator-history
- **operator_operates_mine:** Regina Fuel Company → No 4 Mine; 1975-02-19 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Ratliff James Delbert-Danny L & Donald E → Regina Fuel Company; 1975-02-19 to current/open; source msha-controller-operator-history