# Relationship history for MSHA mine 3003305

Current hierarchy: **William D  Leo → Ward Pavements Inc → POWERSCREEN PLANT**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **controller_controls_mine:** William D  Leo → POWERSCREEN PLANT; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Ward Pavements Inc → POWERSCREEN PLANT; 1999-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** William D  Leo → Ward Pavements Inc; 1999-10-01 to current/open; source msha-controller-operator-history