# Relationship history for MSHA mine 5001775

Current hierarchy: **United States Government → USDI - National Park Service → Dena Portable Screen Plant # 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

- **operator_operates_mine:** USDI - National Park Service → Dena Portable Screen Plant # 1; 2003-05-27 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** United States Government → Dena Portable Screen Plant # 1; 2003-05-27 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** United States Government → USDI - National Park Service; 2003-05-27 to current/open; source msha-controller-operator-history