Climate: Similar to Mt. Veeder AVA, with cool weather prevailing and smaller diurnal changes. Fairly cool nights and higher elevations help maintain good acidity.
Elevation: 600 to 2200 ft (184 to 675m).
Rainfall: 40 to 50 inches (125cm) annually.
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.