Visit the Grand Coulee Dam

A whopping 1,165 dams line Washington’s waterways, from small irrigation dams, like the five-foot Horn Rapids Dam that fills channels on either side of the Yakima River, to the more than 70 hydroelectric dams that help power cities on both sides of the Cascade curtain.

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 when operating at full capacity.

Visit the dam’s power plant between April and October to see some of the largest turbines in the world, then take a van ride across the 5,223-foot long concrete monolith and gaze out to where the 151-mile long Lake Roosevelt stretches out to the horizon. During the summer months, stick around late into the night for a free, narrated laser light show that splashes color across the face of the dam and tells the story of how, and why, the Grand Coulee was constructed.

—Julie H. Case