# Relationship history for MSHA mine 4703817

Current hierarchy: **Thomas  DeBeck → Four Man Chess, LLC → Impact Crusher KPI s/n 415022**

- 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:** Thomas  DeBeck → Impact Crusher KPI s/n 415022; 2008-09-08 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Speedway Sand & Gravel → Impact Crusher KPI s/n 415022; 2018-02-27 to 2024-05-06; source msha-controller-operator-history
- **controller_controls_operator:** Thomas  DeBeck → Speedway Sand & Gravel; 2018-02-27 to 2024-05-06; source msha-controller-operator-history
- **operator_operates_mine:** Four Man Chess, LLC → Impact Crusher KPI s/n 415022; 2024-05-07 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Thomas  DeBeck → Impact Crusher KPI s/n 415022; 2024-05-07 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Thomas  DeBeck → Four Man Chess, LLC; 2024-05-07 to current/open; source msha-controller-operator-history