# Relationship history for MSHA mine 4503666

Current hierarchy: **Steven P  Smith → Newport Equipment Enterprises, Inc → Smith Quarry**

- 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:** Newport Equipment Enterprises, Inc → Smith Quarry; 2009-06-15 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Steven P  Smith et al → Smith Quarry; 2009-06-15 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Steven P  Smith et al → Newport Equipment Enterprises, Inc; 2009-06-15 to current/open; source msha-controller-operator-history