The tour leaves the bronzed, grass-tufted hills and runs close along the Naches River, almost hidden by the timbered mountains. The Naches Valley narrows to a canyon between towering cliffs of somewhat porous stone, folded and faulted into spire-like forms and palisades. Time-etched rocks project like gargoyles from the canyon walls; porous layers of lava, broken up by moisture and frost, present many color variations.