# Relationship history for MSHA mine 4202636

Current hierarchy: **Darin J  Christensen → Christensen Ready Mix → CRM Portable 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:** Darin J  Christensen → CRM Portable Crusher 1; 2000-05-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Christensen Ready Mix → CRM Portable Crusher 1; 2014-09-24 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Darin J  Christensen → Christensen Ready Mix; 2014-09-24 to current/open; source msha-controller-operator-history