Diamond Mountain is the northernmost mountain appellation in the Mayacamas Range, on the northwest side of the valley floor, above the town of Calistoga. Defined mainly by elevation, vineyards are planted at 400 to 2,200 feet.
Diamond Mountain vineyards receive plenty of sunshine at these elevations and are typically above the coastal fog line. But given its western proximity, the area still easily cools down from early morning and late afternoon Pacific Ocean breezes. The AVA (American Viticultural Area) covers 5,000 acres but just over 500 acres are under vine.
Diamond Mountain soils, mainly weathered, red sedimentary rock and decomposed, volcanic ash, are infertile, quick-draining and produce small, thick-skinned grapes, bursting with chewy tannins.
Cabernet Sauvignon, Merlot, Cabernet Franc, Malbec, Petit Verdot and Zinfandel have great success here.
Like other sub-appellations in Napa Valley, the Diamond Mountain area had no shortage of pioneer winemakers. Rudy von Strasser led the effort for Diamond Mountain to acquire AVA status in 1999.