Spring Mountain AVA is above the town of St. Helena on the eastern slopes of the Mayacamas Mountains. There is no actual Spring Mountain, but the name has traditionally been used for the area, which includes many streams and springs. Spring Mountain was awarded appellation status in 1993 and it includes about 1,000 vineyard acres. Vineyard elevations are high, from 400 to 2,600 feet above sea level. Because of the altitude of most vineyards, which are above the fog line, mornings become warm earlier than vineyards on the valley floor, though the afternoons are cooled by maritime winds. The result is an exceptionally long growing season. Cabernet Sauvignon is the most frequently planted grape by acreage, followed by Merlot, Cabernet Franc and Chardonnay.
Despite its popularity, this grape is quite rare. Less than 10,000 acres are planted worldwide, with the bulk in California. In France, the grape is referred to as Durif. Not to be confused with Syrah, Petite Sirah is a cross of Syrah and Peloursin. The result is darker and fuller.