Sonoma Valley Sonoma County, California The Sonoma Valley AVA encompasses Sonoma County's Sonoma River Valley where it runs down into the San Pablo Bay. Since its creation it has been subdivided into several subappellations. The Sonoma Valley also overlaps the Los Carneros region. Wineries: Benziger Family Winery B. R. Cohn Winery Dunnewood Sebastiani Vineyards & Winery Wellington Vineyards AVAs within the Sonoma Valley: Bennett Valley Sonoma Mountain