# Relationship history for MSHA mine 1103188

Current hierarchy: **Northwest Illinois Construction Company; Helm Group Inc → Northwest Illinois Construction, LLC → Brookville Portable #1**

- 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

- **operator_operates_mine:** Northwest Illinois Construction, LLC → Brookville Portable #1; 2008-03-24 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Northwest Illinois Construction Company et al → Brookville Portable #1; 2008-03-24 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Northwest Illinois Construction Company et al → Northwest Illinois Construction, LLC; 2008-03-24 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Helm Group Inc et al → Northwest Illinois Construction, LLC; 2008-03-24 to current/open; source msha-controller-operator-history