Withrow Moraine and Jameson Lake Drumlin Field erosion resulting from the Missoula Floods, which laid bare many layers of the basalt flows on the edges of the plateau at Grand Coulee and Moses Coulee. Two million years ago the Pleistocene epoch began and Ice age glaciers invaded the area. They scoured the Columbia River Plateau, reaching as far south as the middle of the Waterville Plateau highlands above the Grand Coulee and south to the head of Moses Coulee. In some areas north of the Grand Coulee they were as much as 3 km (10000 feet) thick. Grooves in the exposed granite bedrock are still visible in
Moses Coulee thrasher, sage sparrow, poorwill, mountain bluebird, loggerhead shrike, canyon wren, white-throated swift, golden eagle), plants (sagebrush buttercup, shooting star, sulphur lupine, serviceberry, mock orange, slender cryptantha, Tiehm's rush, big sagebrush, bluebunch wheatgrass and sego lily) and animals (mule deer, least chipmunk, bats, and marmot). Moses Coulee Moses Coulee is a canyon in the Waterville plateau region of Douglas County, Washington. Moses Coulee is the second-largest and westernmost canyon of the Channeled Scablands, located about to the west of the larger Grand Coulee. This water channel is now dry, but during glacial periods, large outburst floods with discharges greater than carved