# Relationship history for MSHA mine 2003415

Current hierarchy: **Gordon A  Thomas → A & J Quality Excavation → A & J Quality Excavation Crusher 1**

- 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:** Gordon A  Thomas → A & J Quality Excavation Crusher 1; 2008-07-31 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** A & J Quality Excavation → A & J Quality Excavation Crusher 1; 2008-08-06 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Gordon A  Thomas → A & J Quality Excavation; 2008-08-06 to current/open; source msha-controller-operator-history