The Grand Coulee Dam is a massive hydroelectric dam on the Columbia River in Washington and is one of the largest concrete structures in the world.

The Grand Coulee Dam, located on the Columbia River in Washington State, is the largest hydroelectric power-producing facility in the United States and one of the largest in the world. Built between 1933 and 1942, it was a key project during the Great Depression and part of Franklin D. Roosevelt's New Deal. The dam provides irrigation, flood control, and hydroelectric power to the Pacific Northwest. It plays a vital role in water management and regional development. The reservoir created by the dam, called Franklin D. Roosevelt Lake, supports agriculture and recreational activities, further enhancing its significance to the area.