# Relationship history for MSHA mine 4104620

Current hierarchy: **Kenneth R Rusty"  Simpson; Stacey M "Shelly" Simpson" → Simpson Crushed Stone LLC → Nemo South Plant**

- 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:** Simpson Crushed Stone → Nemo South Plant; 2006-08-14 to 2012-05-01; source msha-controller-operator-history
- **controller_controls_mine:** Kenneth R  Simpson → Nemo South Plant; 2006-08-14 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Kenneth R  Simpson → Simpson Crushed Stone; 2006-08-14 to 2012-05-01; source msha-controller-operator-history
- **controller_controls_mine:** Kenneth R Rusty"  Simpson et al" → Nemo South Plant; 2009-10-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Simpson Crushed Stone LLC → Nemo South Plant; 2012-05-02 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Kenneth R Rusty"  Simpson et al" → Simpson Crushed Stone LLC; 2012-05-02 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Stacey M Shelly" Simpson et al" → Simpson Crushed Stone LLC; 2012-05-02 to current/open; source msha-controller-operator-history