Grand Coulee Dam

Grand Coulee Dam, Columbia Basin Project, located on the Columbia River in Washington, is one of the largest concrete structures in the world. The original (or main) dam is a straight-gravity type, massive concrete structure consisting of a river overflow spillway section, 1,650 feet long and adjoining abutment sections which give the original dam a total crest length of 4,173 feet. From the lowest point of its granite base, the dam rises to a height of 550 feet. The powerplant is the country's largest hydroelectric plant and generates more power than a million locomotives.

90 miles west of Spokane, Washington on State Highway 155.