Grand Coulee Dam seen as the answer. Efforts to build the Third Powerplant were also influenced by competition with the Soviet Union, which had constructed power plants on the Volga River larger than Grand Coulee. On , 1964, the Columbia River Treaty was ratified and included an agreement by Canada to construct the Duncan, Keenleyside, Mica Dams upstream and the U.S. would build the Libby Dam in Montana. Shortly afterward, Washington Senator Henry M. Jackson, who was influential in constructing the new power plant, announced Reclamation would present the project to Congress for appropriation and funding. To keep up with Soviet competition and
Grand Coulee pumped from the Grand Coulee Dam, into Banks Lake to act as an Equalizing Reservoir and irrigation water source. Evidence of the waterfalls includes a plunge basin where the falls began, immediately south of Coulee City. It contains at least of gravel lower than the open flooring of the land. The river above the falls was shallow and much wider than the gorge. Thus, it wrapped around the lip of the main falls creating lateral falls. These flowed until the recession of the main falls denied them water. Northrup Canyon in Steamboat Rock State Park, contains a dry cataract as