The fauna of the U.S. State of Nevada is mostly species adapted to desert, temperature extremes and to lack of moisture. With an average annual rainfall of only about 7 inches (180 mm), Nevada is the driest – and has the largest percentage of its total area classified as desert – of all states in the United States. Two-thirds of the state is located within the largest desert on the North American continent, the Great Basin Desert, while the lower one-third is the Mojave Desert.