# Relationship history for MSHA mine 3901432

Current hierarchy: **Roger  Krueger; David  Krueger → Krueger Brothers Gravel & Dirt → PORTABLE SCREENER**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **operator_operates_mine:** Krueger Brothers Gravel & Dirt → PORTABLE SCREENER; 1998-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Roger  Krueger et al → PORTABLE SCREENER; 1998-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Roger  Krueger et al → Krueger Brothers Gravel & Dirt; 1998-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** David  Krueger et al → Krueger Brothers Gravel & Dirt; 1998-10-01 to current/open; source msha-controller-operator-history