This map identifies probable wildlife corridor routes from the north end of the Absaroka Range and the north end of the Gallatin Range across Interstate 90 to the Bridger Range. Habitat suitability for grizzly bear and mountain lion was modeled using Montana Gap Analysis coverages for vegetation type and weighted index for road density (developed by Rich Walker) that was derived as a cell-based integration of TIGER road data. Corridor routes were located using a Least-Cost-Path Analysis algorithm that is standard in ArcGRID.

This analysis used a 1-square-kilometer grid size. The routes outlined are only approximate (within a kilometer or two) but are a first approximation of the best habitat available for wildlife movement in this area. "Least-cost routes" refers to the shortest distance through good habitat from Yellowstone to Glacier and does not imply that the route through the Bridgers is better for wildlife movement than other routes. The next stage of analysis will more closely identify these general routes.