# Relationship history for MSHA mine 4703072

Current hierarchy: **Shirley  Washkovick → R & R Wash Materials Inc → HEWITT ROBBINS**

- 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:** Shirley  Washkovick → HEWITT ROBBINS; 1979-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** R & R Wash Materials Inc → HEWITT ROBBINS; 1996-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Shirley  Washkovick → R & R Wash Materials Inc; 1996-05-01 to current/open; source msha-controller-operator-history