# Relationship history for MSHA mine 4502612

Current hierarchy: **William F  Cusick → Port Orchard Sand & Gravel Company Inc → Purdy 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:** Walt  Miles et al → Purdy Pit; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Miles Sand & Gravel Co Inc → Purdy Pit; 1979-01-01 to 1980-03-31; source msha-controller-operator-history
- **controller_controls_operator:** Walt  Miles et al → Miles Sand & Gravel Co Inc; 1979-01-01 to 1980-03-31; source msha-controller-operator-history
- **operator_operates_mine:** Port Orchard Sand & Gravel Company Inc → Purdy Pit; 1980-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** William F  Cusick → Purdy Pit; 1980-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** William F  Cusick → Port Orchard Sand & Gravel Company Inc; 1980-04-01 to current/open; source msha-controller-operator-history