Trade Route Predictions in the North Cascades

This map analyzes the topography and weighting of several factors in order to predict the least costly trade routes from Winthrop to several coastal communities.



This project involved developing hillshades and working with various raster data of the North Cascades region. The goal was to develop a map showing the “least costly” routes from Winthrop, WA to several coastal communities. This will assist archaeological teams with the location of historical Native American trade routes and potential archaeological sites throughout the North Cascades region.


The analysis involved formatting raster data and developing elevation and hillshade data. In addition, the model prioritized proximity to rivers for both consistent access to resources and the typically gradual slope that river valleys flow through. Slope was weighted at 70 percent of consideration and stream distance was weighted at 30 percent. This yielded routes that followed river valleys and the least dramatic topography.

Results and Significance

The resulting cost analysis of potential trade routes highlights several of the least costly paths to and from Winthrop, WA. These routes are potential avenues that Native Americans may have used for travel through the North Cascades. This would help inform the search for archaeological sites throughout the areas.