The state of Nevada is located in the Basin and Range physiographic province and is characterized by an abnormally high heat flow resulting from near-melting conditions in the lower crust and upper mantle. As in many parts of the world, its geothermal resources are primarily associated with young volcanics. Although Nevada lies in the center of a large area of Cenozoic volcanic rocks, ranging in age from 10 to 30 million years old, younger volcanic rocks are found in many areas of the state. These include the Mono Lake Aurora area of southwest Mineral County and adjacent California, southwestern Eureka County, north of Silver Peak in Esmeralda County, the Carson and Virginia Ranges near Reno, Lunar Crater in northeastern Nye County, the north end of the Fish Creek Mountains in northern Lander County, Reveille Valley and the Amargosa Desert in Nye County, Railroad Point in northwestern Humboldt County, and the Winnemucca-Battle Mountain area of north central Nevada