The Potter Valley AVA in Mendocino County is situated just east of the Redwood Valley, near the border with Lake County. Vines are planted between 900 and 1100 feet; soils are bedrock with layers of clay and sand. Rainfall is higher here than in other parts of Mendocino, making this an ideal zone for white grapes. Riesling, at almost 45% is the leading variety, followed by Sauvignon Blanc and then Pinot Noir; a small amount of Zinfandel, Chardonnay and Gewurztraminer. (Wine/Appellations)