# Relationship history for MSHA mine 4502750

Current hierarchy: **Eucon Corporation → De Atley Company Inc → Airway Heights Quarry**

- 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:** Eucon Corporation → Airway Heights Quarry; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** De Atley Company Inc → Airway Heights Quarry; 1979-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Eucon Corporation → De Atley Company Inc; 1979-10-01 to current/open; source msha-controller-operator-history