# Relationship history for MSHA mine 4503619

Current hierarchy: **The Schomac Group Inc → Stampede Sand & Gravel LLC → Stampede Sand & Gravel LLC**

- 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:** Stampede Sand & Gravel LLC → Stampede Sand & Gravel LLC; 2006-11-13 to 2018-04-01; source msha-controller-operator-history
- **controller_controls_mine:** Jessup  Schoff et al → Stampede Sand & Gravel LLC; 2006-11-13 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Jessup  Schoff et al → Stampede Sand & Gravel LLC; 2006-11-13 to 2018-04-01; source msha-controller-operator-history
- **controller_controls_operator:** Anthony P  Vasquez et al → Stampede Sand & Gravel LLC; 2006-11-13 to 2018-04-01; source msha-controller-operator-history
- **operator_operates_mine:** Stampede Sand & Gravel LLC → Stampede Sand & Gravel LLC; 2018-04-02 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** The Schomac Group Inc → Stampede Sand & Gravel LLC; 2018-04-02 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** The Schomac Group Inc → Stampede Sand & Gravel LLC; 2018-04-02 to current/open; source msha-controller-operator-history