Moses Coulee the southern portion of the plateau. These streams had combined into a canyon that drained to the Columbia near the current mouth of Moses Coulee. These side drainages are still visible today along the coulee walls as truncated streambeds, interspersed with gable-like highlands. The Okanogan lobe of the Cordilleran Glacier moved down the Okanogan River valley, covering 500 mi² of the Waterville Plateau and blocked the ancient route of the Columbia River, backing up water to create Glacial Lake Columbia and Lake Spokane. Initially water discharged from Lake Columbia by running up through the head of Grand Coulee and down
East Coulee, Alberta 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 . The community is within Census Division No. 5 and in the federal riding