# Relationship history for MSHA mine 1901181

Current hierarchy: **John P  Healy → Dudley Concrete Inc → Dudley 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: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **operator_operates_mine:** Dudley Concrete Inc → Dudley Plant; 2008-09-15 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** John P  Healy → Dudley Plant; 2008-09-15 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** John P  Healy → Dudley Concrete Inc; 2008-09-15 to current/open; source msha-controller-operator-history