# Relationship history for MSHA mine 3003610

Current hierarchy: **David J  Smith → Smith Sand & Gravel, Inc. → Davis 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: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **operator_operates_mine:** Smith Sand & Gravel, Inc. → Davis Mine; 2007-10-10 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** David J  Smith → Davis Mine; 2007-10-10 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** David J  Smith → Smith Sand & Gravel, Inc.; 2007-10-10 to current/open; source msha-controller-operator-history