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
East Coulee, Alberta a land area of , it had a population density of in 2011. East Coulee, Alberta East Coulee is a community within the Town of Drumheller, Alberta, Canada. It was previously a hamlet within the former Municipal District (MD) of Badlands No. 7 prior to the MD's amalgamation with the former City of Drumheller on January 1, 1998. It is also recognized as a designated place by Statistics Canada. East Coulee is located on Highway 10, approximately southeast of Drumheller's main townsite and northeast of Calgary. It lies in the Red Deer River valley and has an elevation of .