# Relationship history for MSHA mine 2103458

Current hierarchy: **Gary A  Leitzen → Zumbro Falls Sand & Gravel, LLC → Zumbro Falls 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

- **operator_operates_mine:** Zumbro Falls Sand & Gravel, LLC → Zumbro Falls Plant; 2004-07-26 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Gary A  Leitzen et al → Zumbro Falls Plant; 2004-07-26 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Gary A  Leitzen et al → Zumbro Falls Sand & Gravel, LLC; 2004-07-26 to current/open; source msha-controller-operator-history