# Relationship history for MSHA mine 4608157

Current hierarchy: **Blankenship Darrell → Cherry Knoll Mining Inc → Kuhn Ridge Surface**

- 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:** Blankenship Darrell → Kuhn Ridge Surface; 1990-08-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Williams Ireland → Kuhn Ridge Surface; 1992-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Rocky Branch Coal Inc → Kuhn Ridge Surface; 1992-02-01 to 1992-08-16; source msha-controller-operator-history
- **controller_controls_operator:** Williams Ireland → Rocky Branch Coal Inc; 1992-02-01 to 1992-08-16; source msha-controller-operator-history
- **operator_operates_mine:** Cherry Knoll Mining Inc → Kuhn Ridge Surface; 1992-08-17 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Blankenship Darrell → Cherry Knoll Mining Inc; 1992-08-17 to current/open; source msha-controller-operator-history