# Relationship history for MSHA mine 0405478

Current hierarchy: **Linda M  Wenger → Valley Sand & Gravel Inc → Valley Sand & Gravel**

- 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:** Valley Sand & Gravel → Valley Sand & Gravel; 2001-03-01 to 2009-08-12; source msha-controller-operator-history
- **controller_controls_mine:** Michael A  Wenger → Valley Sand & Gravel; 2001-03-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Michael A  Wenger → Valley Sand & Gravel; 2001-03-01 to 2009-08-12; source msha-controller-operator-history
- **operator_operates_mine:** Valley Sand & Gravel Inc → Valley Sand & Gravel; 2009-08-13 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Linda M  Wenger → Valley Sand & Gravel; 2009-08-13 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Linda M  Wenger → Valley Sand & Gravel Inc; 2009-08-13 to current/open; source msha-controller-operator-history