# Relationship history for MSHA mine 4609169

Current hierarchy: **Rick  Coulson → Coalex Inc → Riggs Surface Mine**

- 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:** Coalex Inc → Riggs Surface Mine; 2006-06-02 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Rick  Coulson → Riggs Surface Mine; 2006-06-02 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Rick  Coulson → Coalex Inc; 2006-06-02 to current/open; source msha-controller-operator-history