The Santa Cruz Mountains AVA is an American Viticultural Area centered on the Santa Cruz Mountains. Its territory expands in three California counties, Santa Clara, Santa Cruz and San Mateo. Established in 1981 by the Alcohol and Tobacco Tax and Trade Bureau (TTB), Santa Cruz Mountains AVA was among the first to be defined by its mountain topography. Based on elevation, it largely follows the fog line along the coast, extending down to 800 feet (240 m) on the eastern slope toward San Francisco Bay, 400 feet (120 m) on the western slope to the Pacific Ocean and extending toward the ridgecrests at 3000+ feet elevation.