# Relationship history for MSHA mine 2103827

Current hierarchy: **Cemstone Concrete Solutions → Dakota Aggregates LLC → Portable Screener #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: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **controller_controls_mine:** Cemstone Concrete Solutions et al → Portable Screener #1; 2013-03-25 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Dakota Aggregates LLC → Portable Screener #1; 2014-07-10 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Cemstone Concrete Solutions et al → Dakota Aggregates LLC; 2014-07-10 to current/open; source msha-controller-operator-history