# Relationship history for MSHA mine 4703667

Current hierarchy: **Robert M  Shea → WINGRA STONE COMPANY → PLANT # 11 PORTABLE SCREENER**

- 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:** Robert M  Shea → PLANT # 11 PORTABLE SCREENER; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** WINGRA STONE COMPANY → PLANT # 11 PORTABLE SCREENER; 2012-08-30 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Robert M  Shea → WINGRA STONE COMPANY; 2012-08-30 to current/open; source msha-controller-operator-history