Sonoma County, California Unknown to many, Sonoma County located in Northern California is actually bigger than its neighbor, Napa County. Sonoma has a famous gap region, known as the Petaluma Gap, that provides a break in the the coastal ranges and is Sonoma County’s newest AVA. The “Gap” is actually a wind gap named after a coastal mountain opening that stretches east from the Pacific Ocean to the south of the San Pablo Bay. Closest to the Sonoma Coast is the famous Russian River Valley AVA known for its high-quality, elegant Pinot Noir and Chardonnay. To the north of the Russian River lies the warmer Dry Creek Valley and Alexander Valley AVA’s producing a wide range of grape varieties including excellent Zinfandels, Sauvignon Blanc, Rhône varietals (Syrah, Grenache, etc), and Cabernet Sauvignon. Other vineyard areas to watch out for premium wine are Sonoma Coast AVA, Anderson Valley, and Mendocino County.