The Los Carneros AVA is located in both Sonoma and Napa counties and received its AVA status in 1983. The Carneros region covers 90 square miles and is centered along the low-lying hills of the Mayacamas range north of San Pablo Bay. The region features a sloping elevation ranging from 400 feet in the foothills to near sea level at San Pablo Bay. Los Carneros is settled by morning fog and moderately cool afternoons with strong winds off the bay. The soils are made of clay and are very shallow allowing for poor drainage. The winds coming off the San Pablo Bay and shallow soil force the vines to struggle and can delay the grapes from ripening, occasionally causing losses in yield and production. The slower ripening allows the grapes to develop complex flavors and balanced acidity. The cooler climate has made Los Carneros a premier region for the cultivation of cooler climate varietals like Pinot Noir and Chardonnay.