John Day Dam, Oregon

A federal dam on the Columbia River, the John Day Dam produces enough electricity (more than 2 million kilowatts) to power all of Seattle. The dam and lock system were completed in 1968, and soon attracted the Harvey Aluminum Corporation (now Goldendale Aluminum), which built a smelter on the Washington side of the dam. The third largest hydroelectric plant in the USA, and 25th largest in the world. It also has the deepest lock in the country, raising and lowering ships traveling on the Columbia River 113 feet.