# Relationship history for MSHA mine 4503627

Current hierarchy: **Pamp  Maiers → AAA Ready-Mix Inc II → Hiawatha Wash Plant**

- 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

- **operator_operates_mine:** AAA Ready-Mix Inc II → Hiawatha Wash Plant; 2007-03-20 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Pamp  Maiers → Hiawatha Wash Plant; 2007-03-20 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Pamp  Maiers → AAA Ready-Mix Inc II; 2007-03-20 to current/open; source msha-controller-operator-history