# Relationship history for MSHA mine 1302212

Current hierarchy: **Donald  Dusek; Ken  Dusek → Dusek Sand & Gravel Ltd → DUSEK SAND & GRAVEL LTD.**

- 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:** Dusek Sand & Gravel Ltd → DUSEK SAND & GRAVEL LTD.; 1997-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Donald  Dusek  et al → DUSEK SAND & GRAVEL LTD.; 1997-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Donald  Dusek  et al → Dusek Sand & Gravel Ltd; 1997-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Ken  Dusek  et al → Dusek Sand & Gravel Ltd; 1997-04-01 to current/open; source msha-controller-operator-history