None, however, is as impressive as the Grand Coulee Dam, just 90 miles west of Spokane.
Built from 1933 to 1942, the 550-foot-tall dam harnesses the power of more than 6 trillion gallons of water and, as the largest hydropower producer in the U.S., provides hydroelectric power to 11 states as well as irrigation to a half million acres of arid land. Shorter but wider than the Hoover Dam, the Grand Coulee can produce 6,809 megawatts of electricity