A commonly ignored key ingredient in large-scale container network assignment is an impedance-driven geovisualization of optimal routes. In this study, we propose linear optimization models for both trip generation and trip assignment using dynamic programming on a GIS platform, which includes maps and data that are used to develop and generate trips. The proposed models are applied to intermodal railroad routes mostly in the United States. Dendritic optimal networks are figures visually depicting all optimal branches for the network.