Grand Coulee is an ancient river bed in the U.S. state of Washington. This National Natural Landmark stretches for about 60 miles (100 km) southwest from Grand Coulee Dam to Soap Lake, being bisected by Dry Falls into the Upper and Lower Grand Coulee.
Grand Coulee, below Dry Falls. The layering effect of periodic basalt lava flows is visible.
Looking northward in Grand Coulee.
Steamboat Rock in the Grand Coulee.
Part of the Grand Coulee has been dammed and filled with water as part of the Columbia Basin Project.
Grand Coulee Dam is a concrete gravity dam on the Columbia River in the U.S. state of Washington, built to produce hydroelectric power and provide irrigation water. Constructed between 1933 and 1942, Grand Coulee originally had two powerhouses. The third powerhouse ("Nat"), completed in 1974 to increase energy production, makes Grand Coulee the largest power station in the United States by nameplate capacity at 6,809 MW.
Grand Coulee Dam
The dam site before construction, looking south
The east-side cofferdam after the west base was complete
Base of the dam in 1938