# Relationship history for MSHA mine 3200903

Current hierarchy: **Michael  Mikkelsen → Border Aggregate, LLC → Portable 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: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** Border Aggregate, LLC → Portable Plant; 2011-07-15 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Michael  Mikkelsen → Portable Plant; 2011-07-15 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Michael  Mikkelsen → Border Aggregate, LLC; 2011-07-15 to current/open; source msha-controller-operator-history