# Relationship history for MSHA mine 4607927

Current hierarchy: **Blankenship Darrell → Cherry Knoll Mining Inc → Blue Ridge No 105**

- 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:** Cherry Knoll Mining Inc → Blue Ridge No 105; 1990-08-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Blankenship Darrell → Blue Ridge No 105; 1990-08-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Blankenship Darrell → Cherry Knoll Mining Inc; 1990-08-01 to current/open; source msha-controller-operator-history