# Relationship history for MSHA mine 0203041

Current hierarchy: **Edward J  Robson → Robson Ranch Arizona Const → Aggregate Products**

- 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:** Robson Ranch Arizona Const → Aggregate Products; 2004-04-02 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Edward J  Robson → Aggregate Products; 2004-04-02 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Edward J  Robson → Robson Ranch Arizona Const; 2004-04-02 to current/open; source msha-controller-operator-history