# Relationship history for MSHA mine 3609143

Current hierarchy: **Donna J  Kehr → Material Girl Sand & Gravel ,LLC → Material Girl Sand & Gravel, LLC**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-18T09:31:49.615908+00:00

## Valid-time edges

- **operator_operates_mine:** Material Girl Sand & Gravel ,LLC → Material Girl Sand & Gravel, LLC; 2003-05-13 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Donna J  Kehr → Material Girl Sand & Gravel, LLC; 2003-05-13 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Donna J  Kehr → Material Girl Sand & Gravel ,LLC; 2003-05-13 to current/open; source msha-controller-operator-history