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
Etzikom Coulee of at its origin east of Stirling Lake (to which it is connected by the Sluice Gate Channel) to an elevation of at its mouth at Pakowki Lake, over a length of more than . The coulee builds a canyon up to deep. Etzikom Coulee Etzikom Coulee is a coulee located in Southern Alberta, Canada. The waterway was formed as a glacial spillway channel at the end of the last ice age. The Etzikom Coulee begins northeast of the town of Stirling, and makes its way southeast of the Hamlet of Wrentham, after that it passes by the Hamlet of