St. Helena is a city in Napa County, California. It is part of the North Bay region of the San Francisco Bay Area. The population was 5,814 at the 2010 census. The city’s American Viticultural Area includes 416 vineyards encompassing 6,800 acres of planted vineyards. St. Helena is also the location of The Culinary Institute of America at Greystone and a campus of Napa Valley College . Sonoma County Airport Taxi can transports you from Saint Helena Sonoma County Airport , San Francisco Airport, San Jose International Airport, and Sacramento International Airport for the best price