Moses Coulee cuts into the Waterville plateau in Douglas County, Washington. It is to the west of and roughly parallel to the more famous Grand Coulee. The mouth of Moses Coulee discharges into the Columbia River at the Great Gravel Bar of Moses Coulee, a National Natural Landmark which was designated a landmark because it is one of the largest examples of bars created by outburst floods of Lake Missoula over the Channeled Scablands of Washington.