Roads destroy, degrade, and isolate wildlife habitats. Wildlife crossing structures are often used to mitigate the impacts roads have on wildlife. The Washington State Department of Transportation has created multiple crossing structures along Interstate-90 (I-90) in a critical area for maintaining connectivity in the Cascade Range near Snoqualmie Pass. Monitoring species composition and activity in areas in and around crossings structures is essential for evaluating their effectiveness because expected use of a given structure by a species is contingent on the species occurring there. Despite the ecological importance of bats and the effect roads have on their access to foraging, breeding, and roosting habitat, investigations into whether crossing structures facilitate bat movements in road-fragmented areas are relatively uncommon. We evaluated species presence and activity of insect-eating bats along I-90 where it intersects with wildlife underpasses to investigate whether bats might preferentially cross the highway at crossing structures. To monitor activity patterns and species composition of bats, we recorded echolocation calls at 6 locations along I-90: 3 with underpasses and 3 without. For each location, we placed a bat detector immediately north of the highway, one immediately south of the highway, and one inside the forest 300-500 m away from the highway for 2 consecutive nights during 3 different recording sessions from July-August of 2020 We used bat-call analysis software and statistical modeling to examine bat activity along the highway where underpasses are present, where underpasses are absent, and in forest habitats adjacent to the highway. All bat species detected in the adjacent forest habitats were detected along the highway. Total bat activity was higher near the highway than in the forest habitats, but not different between locations with underpasses and those without. Detected species were also grouped into guilds based on the frequency of their echolocation calls. Analysis of guild-specific activity revealed that some bats responded differently to roads or their surrounding habitat features depending on species. Several factors, including forest proximity to the highway, could have influenced activity differences observed here. More intensive monitoring efforts of bats at crossing structures along I-90 and other major highways are needed to understand the mechanisms behind these patterns. However, creating structures that reduce the impacts roads have on bats starts with understanding where they are and why. This study was the first step in gaining this understanding for bats along I-90 in Washington State.