Grand Coulee of the continental shelf. The web-like formation can be seen from space. Mountains of gravel as tall as 40-story buildings were left behind; boulders the size of small houses and weighing many tons were strewn about the landscape. Grooves in the exposed granite bedrock are still visible in the area from the movement of glaciers, and numerous erratics are found in the elevated areas to the northwest of the coulee. Early theories suggested that glaciers diverted the Columbia River into what became the Grand Coulee and that normal flows caused the erosion observed. In 1910 Joseph T. Pardee described a
Grand Coulee, Washington Grand Coulee, Washington Grand Coulee is a city in Grant County, Washington, United States. The population was 988 at the 2010 census. Grand Coulee was officially incorporated on November 6, 1935. It is located above the Grand Coulee Dam and next to North Dam. Grand Coulee is located at (47.939706, -119.001597). According to the United States Census Bureau, the city has a total area of , of which, is land and is water. As of the census of 2010, there were 988 people, 474 households, and 246 families residing in the city. The population density was . There were 554