Described as a mountain island, the climate of this Texas appellation is cooler, wetter and more biologically diverse than the Chihuahua desert which surrounds it. Receiving twice the annual rainfall of the desert, Davis Mountain AVA covers 270,000 acres in the Trans-Pecos region of west Texas, with about 50 acres under vine. The area was formed during a slow-motion tectonic and volcanic catastrophe, the same one which formed the front range of the Rockies. The soil of the region is composed of granitic, porphrytic and volcanic rocks, as well as limestone. The soils are porous and offer superior water drainage. Located within Jeff Davis County, in a mountainous region known as the Davis Mountains (second highest range in the state), the elevation of the viticultural region ranges from 4,500-8,300 feet.