# Relationship history for MSHA mine 3003690

Current hierarchy: **Justin  Sokolowski → Seward Sand & Gravel Inc → Metso ST272 Screen #R2721525**

- 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

- **controller_controls_mine:** David R  Beisler → Metso ST272 Screen #R2721525; 1983-04-14 to 2022-11-30; source msha-controller-operator-history
- **operator_operates_mine:** Seward Sand & Gravel Inc → Metso ST272 Screen #R2721525; 2009-06-02 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** David R  Beisler → Seward Sand & Gravel Inc; 2009-06-02 to 2022-11-30; source msha-controller-operator-history
- **controller_controls_mine:** Justin  Sokolowski → Metso ST272 Screen #R2721525; 2022-12-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Justin  Sokolowski → Seward Sand & Gravel Inc; 2022-12-01 to current/open; source msha-controller-operator-history