# Relationship history for MSHA mine 2700452

Current hierarchy: **Lloyd A  Drew → L A Drew Inc → Portable Screening 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:** Lloyd A  Drew → Portable Screening Plant; 1990-04-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** L A Drew Inc → Portable Screening Plant; 2011-07-28 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Lloyd A  Drew → L A Drew Inc; 2011-07-28 to current/open; source msha-controller-operator-history