The Dry Creek Valley AVA is an American Viticultural Area in Sonoma County, California, located northwest of the town of Healdsburg. The valley is formed by Dry Creek, a tributary of the Russian River, and is approximately 16 miles (25.7 km) long and 2 miles (3.2 km) wide. The appellation benefits from the close proximately of the Lake Sonoma reservoir for irrigation in this relatively dry area. At the turn of the 20th century, Dry Creek Valley was one of California's most prominent producers of Zinfandel. During Prohibition, much of the valley was converted to plum, pear, and prune trees, and much of the fruit was processed by Sunsweet Growers in Healdsburg. Since the resurgence of wine grape production in the 1970s, Cabernet Sauvignon and Zinfandel have become the most planted varietals, and Dry Creek Valley AVA has become one of the state's top Zinfandel producers.