A rustic stone Vista House overlooks the scarred walls of the extinct falls, where a cataract many times greater than Niagara once plunged, a gigantic waterfall with a sheer drop of 417 feet and a width of nearly 3 miles. The dry falls were caused by the erosive glacial waters, the ice cap having changed the course of the Columbia River. Various geologic periods are illustrated in the strata of the walls, and leaves and trees are fossilized in the strata. A trail winds from Vista House down the face of the cliff to the bottom of the falls. At the base of the cliff are Perch and Deep lakes.

Dry Coulee extends east and south into the Hartline Basin. The erosion of this lower half of the Grand Coulee is even more interesting than that of the upper coulee. Because of the presence of a narrow outlet into Hartline Basin, glacial waters coursed through interlacing channels. At times spread out over a width of 13 miles, they rushed down the southern slope or a fold, forming a series of rapids and waterfalls that carved out the wildest and most spectacular of the abandoned channels of the scablands. Monads, grim relics of rocks not eroded by the sand-laden water, rise from the canyon floor.