# Relationship history for MSHA mine 4605025

Current hierarchy: **Quaker State Corp → Valley Camp Coal Company → Donaldson Culm/Bank (1)**

- 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:** Quaker State Corp → Donaldson Culm/Bank (1); 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Valley Camp Coal Company → Donaldson Culm/Bank (1); 1976-02-11 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Quaker State Corp → Valley Camp Coal Company; 1976-02-11 to current/open; source msha-controller-operator-history