California
If 50 American states produce wine, Californian production alone represents approximately 85% of the country's production, making this state the 4th largest producer in the world behind Italy, France and Spain. The climate is strongly influenced by the Pacific Ocean which at this latitude is a cold ocean. The wine-growing regions located near the Pacific have an oceanic climate becoming Mediterranean the further inland you go from the ocean and it becomes more continental near the Sierra Nevada. Bays and openings to the sea, such as San Pablo Bay, act as thermal regulators on viticulture, particularly in Napa and Sonoma Valley.
The sub-region: Central Coast
Stretching approximately 280 miles (450 km), the Central Coast region covers some of California's most famous AVAs outside of Napa and Sonoma counties, including Paso Robles, Chalone, the Santa Cruz Mountains and the Santa Maria Valley. The region's rugged, mountainous topography was caused by years of tectonic change, and the famous San Andreas Fault cuts off much of the AVA from the rest of the United States. The Santa Lucia Mountains, Galiban Range, and Santa Cruz Mountains all pass through this part of California and greatly influence the terroir of the Central Coast wine growing areas.