# Relationship history for MSHA mine 0302019

Current hierarchy: **Steve R  Hackman → Ozark Premium Sand, LLC → Ozark Premium Sand Desha 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

- **controller_controls_mine:** Steve R  Hackman et al → Ozark Premium Sand Desha Plant; 2008-06-18 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Ozark Premium Sand, LLC → Ozark Premium Sand Desha Plant; 2011-09-02 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Steve R  Hackman et al → Ozark Premium Sand, LLC; 2011-09-02 to current/open; source msha-controller-operator-history