The Havasu Wilderness provides a primitive mountainous desert experience.  Topock Marsh Unit–4,000 acres of Topock Marsh.  Topock Gorge–Colorado River, backwater bays, beautiful desert mountains, and cliffs.  Havasu wilderness measures 14,606 acres.  Wildlife includes the endangered Yuma Clapper Rail, desert bighorn sheep, variety of marsh birds, and neotropical migrant land birds.  In the desert uplands, there are a variety of reptiles.