Libby Dam is the culmination of years of effort on the part of both the United States and Canada to develop a flood control plan for the Columbia River basin. The Kootenai River is the third largest tributary of the Columbia River, contributing almost 20 percent of the total water in the lower Columbia. The dam stands 422 feet tall and about one-half mile long and creates a reservoir (Lake Koocanusa) which extends 42 miles into Canada. Construction began in 1966 and the dedication ceremony in 1975 marked the beginning of commercial power generation. The Columbia River Treaty was established between the governments of Canada and the United States before the dam was built. This treaty paved the way for cooperative development of the Columbia River basin while simultaneously aiding future negotiations between the two countries. Construction of the dam required relocation of about 60 miles of Burlington Northern's main railroad line and 52 miles of Montana State Highway 37, construction of 51 miles of Forest Service roads, and relocation or adjustment of other roads, facilities, utilities, and services effected by Lake Koocanusa. The town of Rexford was moved out of the lake area. In Canada there were effected communities, roads and railroad sections too. The railroad relocation required construction of a 7-mile long tunnel. The Flathead Tunnel is the world's 7th longest railroad tunnel. One of the most impressive features of the dam is the Treaty Tower which reaches 57.5 feet above the top of the dam It is distinguished by the 70-ton granite sculpture on its face. An international committee chose Albert Wein's design from a contest field of 250 entries. The sculpture symbolizes the natural and man-made forces on the Kootenai River, and commemorates the treaty between the two nations. The Souse Gulch Day Use Area is open daily after the first week of May. The day use area is located immediately adjacent to the Visitor Center. Click here for more information.