# Relationship history for MSHA mine 4300748

Current hierarchy: **Jacob D  Simpson → Simpson Dirtworx llc → Simpson Sand and Gravel**

- 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:** Simpson Dirtworx llc → Simpson Sand and Gravel; 2013-06-27 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Jacob D  Simpson → Simpson Sand and Gravel; 2013-06-27 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Jacob D  Simpson → Simpson Dirtworx llc; 2013-06-27 to current/open; source msha-controller-operator-history