# Relationship history for MSHA mine 2402407

Current hierarchy: **David A  Smith → Smith Contracting Inc. → Hartl Mini Track 503 Rock 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: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **controller_controls_mine:** David A  Smith → Hartl Mini Track 503 Rock Crusher; 2003-07-21 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Smith Contracting Inc. → Hartl Mini Track 503 Rock Crusher; 2005-05-20 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** David A  Smith → Smith Contracting Inc.; 2005-05-20 to current/open; source msha-controller-operator-history