East Side Tunnel, Through Piegan Mountain at Going-to-the-Sun Road, West Glacier, Flathead County, MT

Significance: The East Side Tunnel is one of approximately seventeen prominent masonry and concrete structures on Going-to-the-Sun Road in Glacier National Park. The 51-mile stretch of scenic road is significant as a unique engineering accomplishment of the early twentieth century, and as the first product of a 1925 cooperative agreement between the National Park Service and the Bureau of Public Roads. The East Side Tunnel is unique in that its construction was heavily dependent upon hand labor, unlike the majority of other structures on the road.
Survey number: HAER MT-80
Building/structure dates: 1931 Initial Construction