# Relationship history for MSHA mine 0202973

Current hierarchy: **Canyon Contracting Services Inc → Canyon Redi-Mix → Canyon Concrete No 2231**

- 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

- **operator_operates_mine:** Canyon Concrete → Canyon Concrete No 2231; 2002-05-07 to 2005-10-02; source msha-controller-operator-history
- **controller_controls_mine:** Tom  Sanders → Canyon Concrete No 2231; 2002-05-07 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Tom  Sanders → Canyon Concrete; 2002-05-07 to 2005-10-02; source msha-controller-operator-history
- **operator_operates_mine:** Canyon Redi-Mix → Canyon Concrete No 2231; 2005-10-03 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Canyon Contracting Services Inc → Canyon Concrete No 2231; 2005-10-03 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Canyon Contracting Services Inc → Canyon Redi-Mix; 2005-10-03 to current/open; source msha-controller-operator-history