Following the Russian River from Healdsburg out to Guerneville, the low lying plain southeast of Healdsburg to Sebastopol is known as the Russian River Valley. The southern part of the grape growing region is one of the coolest in Sonoma County. It is the first region to feel the effects of the afternoon fog that arises from Tomales Bay and the last to see the mid-morning sun. Early ripening varieties such as Chardonnay and Pinot Noir are well suited to this climate as are other white varieties such as Sauvignon Blanc and Gewürztraminer. In the northern part of the valley near Windsor and Santa Rosa, both Zinfandel and Cabernet sauvignon are planted and harvested quite successfully. Even in the fog-infested Green Valley area near Forestville there are vineyards of Cabernet Sauvignon which may be harvested late in the season but still produce exceptionally fine fruit. (Courtesy of Sonoma County Wineries Association)