# Relationship history for MSHA mine 4703309

Current hierarchy: **John  Carew → CAREW CONCRETE & SUPPLY CO., INC. → PORTABLE SCREEN 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:** John  Carew → PORTABLE SCREEN PLANT; 1993-08-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** CAREW CONCRETE & SUPPLY CO., INC. → PORTABLE SCREEN PLANT; 2002-05-21 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** John  Carew → CAREW CONCRETE & SUPPLY CO., INC.; 2002-05-21 to current/open; source msha-controller-operator-history