Video: 'Coulee Dam Opened (1941)'

(Saturday, March 22, 1941, 1:25 p.m. PST) — Grand Coulee Dam on the Columbia River in the U.S. state of Washington began producing electrical power for the Pacific Northwest today, two years ahead of schedule.

Grand Coulee originally had only two powerhouses. The third powerhouse (“Nat”), completed in 1974 to increase energy production, making Grand Coulee the largest power station in the United States by nameplate-capacity at 6,809 megawatts.

Video: 'Grand Coulee Dam: A Man-Made Marvel (Full Movie)'