Climate: Similar to Mt. Veeder AVA, with cool weather prevailing and smaller diurnal changes. Fairly cool nights and higher elevations help maintain good acidity.
Soils: Primarily sedimentary; weathered sandstone/shale, loamy and friable in texture. Drainage is high, fertility low.
Principal varieties & characteristics: Cabernet Sauvignon, Merlot, Zinfandel: Powerful, firm, blackberry-currant flavors and often richly tannic, with excellent acidity for aging. Chardonnay, Viognier: Sinewy, firm and not as fruity as those of the valley floor, revealing more citrus and stone fruit flavors.
Principle Wineries: