# Relationship history for MSHA mine 3002590

Current hierarchy: **Walter F  Przybycien → Manitou Sand & Gravel Company Inc → Pease 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

- **controller_controls_mine:** Walter F  Przybycien → Pease Pit; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Manitou Sand & Gravel Company Inc → Pease Pit; 1981-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Walter F  Przybycien → Manitou Sand & Gravel Company Inc; 1981-06-01 to current/open; source msha-controller-operator-history