# Relationship history for MSHA mine 4606650

Current hierarchy: **Crawford Lewis C Jr → Calvin Coal Augering Inc → Colony Bay Coal Co 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:** Calvin Coal Augering Inc → Colony Bay Coal Co Surface Mine; 1983-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Crawford Lewis C Jr → Colony Bay Coal Co Surface Mine; 1983-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Crawford Lewis C Jr → Calvin Coal Augering Inc; 1983-05-01 to current/open; source msha-controller-operator-history