The northwestern tip of the Big Maria Mountains, rising to about 2,000 feet above sea level, gives way to the broad, flat plains of Rice Valley within this Wilderness. Rice Valley is the southern end of a vast sheet of sand extending from Cadiz Valley in the north southward across Ward Valley. Relatively small as far as dunes go, the buff-colored sand of Rice Valley rises 30 to 40 feet above the valley floor and stretches in a long, narrow band along the middle of the region. Beyond the mountains, this is a Wilderness of sand.