# Relationship history for MSHA mine 4703761

Current hierarchy: **NI Sand Holdings LLC → Northern Industrial Sand LLC → Dovre Dry Plant Site**

- 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:** NI Sand Holdings LLC → Dovre Dry Plant Site; 2015-04-23 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Northern Industrial Sand LLC → Dovre Dry Plant Site; 2015-06-25 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** NI Sand Holdings LLC → Northern Industrial Sand LLC; 2015-06-25 to current/open; source msha-controller-operator-history