# Relationship history for MSHA mine 5001836

Current hierarchy: **Colas S A → SERB → North Operations-Wash Plant #2**

- 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  Crawley → North Operations-Wash Plant #2; 1995-03-01 to 2000-08-31; source msha-controller-operator-history
- **controller_controls_mine:** Colas S A → North Operations-Wash Plant #2; 2000-09-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** University Redi-Mix Concrete Products → North Operations-Wash Plant #2; 2006-03-31 to 2018-04-30; source msha-controller-operator-history
- **controller_controls_operator:** Colas S A → University Redi-Mix Concrete Products; 2006-03-31 to 2018-04-30; source msha-controller-operator-history
- **controller_controls_operator:** Gordon  Crawley → University Redi-Mix Concrete Products; 2006-03-31 to 2000-08-31; source msha-controller-operator-history
- **controller_controls_mine:** Colas S A → North Operations-Wash Plant #2; 2018-03-30 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** SERB → North Operations-Wash Plant #2; 2018-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Colas S A → SERB; 2018-05-01 to current/open; source msha-controller-operator-history