# Relationship history for MSHA mine 2003688

Current hierarchy: **Earl R  Dubey → Alpena Aggregate Inc → Hazemag/Metsco Crusher Astec Screen**

- 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:** Earl R  Dubey → Hazemag/Metsco Crusher Astec Screen; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Alpena Aggregate Inc → Hazemag/Metsco Crusher Astec Screen; 2025-06-08 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Earl R  Dubey → Alpena Aggregate Inc; 2025-06-08 to current/open; source msha-controller-operator-history