The Interstate 90 corridor through Snoqualmie Pass is positioned between a number of important National Forests, wilderness areas and National Parks that provide refuge for a diverse array of wildlife species. As a result, the highway has created barriers to ecological connectivity for wildlife within and among these areas. The location has high levels of traffic, with an average of 28,000 vehicles passing through it on weekdays, and as many as 58,000 on weekends. Moreover, traffic levels are expected to double on this section of I-90 over the next 20-30 years. The Washington State Department of Transportation (WSDOT) plans to widen this section of road from four lanes to six lanes, to accommodate increased traffic and higher speeds, and to enhance safety. As part of the widening project, WSDOT is investigating ways to resolve and address wildlife connectivity issues in the course of construction. WSDOT plans to build crossing structures to enhance ecological connectivity at Connectivity Enhancement Areas (CEAs) throughout the 15-mile project area to link habitats for multiple species and ecological processes over time. Through this project WTI will work with WSDOT and a multi-jurisdictional Wildlife Monitoring Technical Committee to develop a Wildlife Monitoring Plan that will guide the design and implementation of pre- and post-construction monitoring of ecological connectivity for wildlife.