Foster Coulee Cordilleran Glacier moved down the Okanogan River valley and blocked the ancient route of the Columbia River, backing up water to create Glacial Lake Columbia. Initially, floodwater discharged from Glacial Lake Columbia by running up through the head of Grand Coulee and down through Foster Coulee to rejoin the Columbia River. After the floods, meltwater from the glacier reversed course and flowed east through the coulee, forming a hanging valley above the west rim of Grand Coulee and a debris fan on the Grand Coulee floor that can be seen today. As the glacier moved further south, Foster Coulee was
Coulee City, Washington Coulee City, Washington Coulee City is a town in Grant County, Washington. The population was 562 at the 2010 census. The town was named after nearby Grand Coulee. Coulee City was officially incorporated on May 10, 1907. Coulee City is located at (47.611942, -119.290904). According to the United States Census Bureau, the town has a total area of , all of it land. As of the census of 2010, there were 562 people, 265 households, and 150 families residing in the town. The population density was . There were 331 housing units at an average density of . The racial