# Relationship history for MSHA mine 4003227

Current hierarchy: **Todd  Carson → B & W Excavation, LLC → B & W Portable Crusher**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **operator_operates_mine:** B & W Excavation, LLC → B & W Portable Crusher; 2004-05-20 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Todd  Carson et al → B & W Portable Crusher; 2004-05-20 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Todd  Carson et al → B & W Excavation, LLC; 2004-05-20 to current/open; source msha-controller-operator-history