# Relationship history for MSHA mine 3503273

Current hierarchy: **Hutchinson Ray → Columbia Western Crushing → Portable Crusher Number 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: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **operator_operates_mine:** Columbia Western Crushing → Portable Crusher Number 1; 1987-03-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Hutchinson Ray → Portable Crusher Number 1; 1987-03-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Hutchinson Ray → Columbia Western Crushing; 1987-03-01 to current/open; source msha-controller-operator-history