# Relationship history for MSHA mine 4105176

Current hierarchy: **Stacey M Shelly" Simpson; Kenneth R "Rusty"  Simpson" → Simpson Sand & Gravel LLC → Woodley Sand Pit**

- 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 Sand & Gravel LLC → Woodley Sand Pit; 2016-03-17 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Stacey M Shelly" Simpson et al" → Woodley Sand Pit; 2016-03-17 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Stacey M Shelly" Simpson et al" → Simpson Sand & Gravel LLC; 2016-03-17 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Kenneth R Rusty"  Simpson et al" → Simpson Sand & Gravel LLC; 2016-03-17 to current/open; source msha-controller-operator-history