# Relationship history for MSHA mine 4300738

Current hierarchy: **Kenneth M  Dow; Matthew S  Dow → D & D Excavating, Inc. → Portable Crusher**

- 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:** Matthew S  Dow et al → Portable Crusher; 2011-06-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** D & D Excavating, Inc. → Portable Crusher; 2012-05-02 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Matthew S  Dow et al → D & D Excavating, Inc.; 2012-05-02 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Kenneth M  Dow et al → D & D Excavating, Inc.; 2012-05-02 to current/open; source msha-controller-operator-history