# Relationship history for MSHA mine 4703497

Current hierarchy: **Eldon L  Duncan → Wisconsin Specialty Sands, Inc. → Hager City 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:** Eldon L  Duncan → Hager City Plant; 2006-06-27 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Wisconsin Specialty Sands, Inc. → Hager City Plant; 2007-03-13 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Eldon L  Duncan → Wisconsin Specialty Sands, Inc.; 2007-03-13 to current/open; source msha-controller-operator-history