# Relationship history for MSHA mine 3402078

Current hierarchy: **Kenneth K  Wert → General Materials Inc → 63rd Street Sand 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:** Larry H  Lemon  et al → 63rd Street Sand Plant; 1979-05-01 to 2009-12-03; source msha-controller-operator-history
- **operator_operates_mine:** General Materials Inc → 63rd Street Sand Plant; 2009-02-17 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Larry H  Lemon  et al → General Materials Inc; 2009-02-17 to 2009-12-03; source msha-controller-operator-history
- **controller_controls_mine:** Kenneth K  Wert → 63rd Street Sand Plant; 2009-12-04 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Kenneth K  Wert → General Materials Inc; 2009-12-04 to current/open; source msha-controller-operator-history