It’s rare for an American Viticultural Area’s name to be so descriptive of its geophysical nature.
But in the northwestern corner of Sonoma County, on stark, hardscrabble ridgelines overlooking Lake Sonoma, you’ll find the AVA known as Rockpile.
The name comes from Rockpile Ranch, which at one time spanned 20,000 acres devoted primarily to cattle and sheep. As the story goes, Sheriff Tennessee Bishop used prisoners to grade the roads leading to his mountain ranch, and the cons dubbed it “rockpile.”
The Rockpile AVA encompasses nearly 15,000 acres, of which fewer than 160 are planted to grapevines. This makes it one of the smallest AVAs in the United States in terms of acreage planted.
Approximately 2,500 of the Rockpile acres overlap the Dry Creek Valley viticultural area to the southeast. Vineyards range in elevation from 800 to nearly 2,100 feet.
The area is known for intense, highly-defined renditions of Zinfandel, Petite Sirah and Cabernet Sauvignon. These varieties evolve dramatically from the spare, demanding soils that are above the fog line. That elevation provides extra sunshine that enables the grapes to ripen fully and evenly in most vintages.
And let’s not neglect the key role that wind plays. Being at a higher elevation, Rockpile receives the full force of the coastal breezes that typically sweep over the neighboring valleys.
It’s not just the velocity of the wind, but also the high percentage of the day in which it blows. Gusts of 3-5 mph are experienced around the clock, occasionally increasing to 10-15 mph.
The winds stress the vines by further drying out what little water retention there may be in the soil. This insures that there will be little or no rot in Rockpile fruit, which provides an added bonus of limiting the need for herbicide or pesticide use in the vineyards.
While the “defining factors” of some AVAs are a bit “iffy,” there are many geographic and geologic features that separate Rockpile from its neighboring appellations. The combination of an elevation requirement, extreme terrain and a unique climate make the vineyards and resulting wines unlike anything from Sonoma County… California… or anywhere else in the world.
