# Relationship history for MSHA mine 4606469

Current hierarchy: **William F  Blackburn III → Mingo Coal & Coke Inc → no 2**

- 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:** Mingo Coal & Coke Inc → no 2; 1981-12-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** William F  Blackburn III → no 2; 1981-12-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** William F  Blackburn III → Mingo Coal & Coke Inc; 1981-12-01 to current/open; source msha-controller-operator-history