While Rockpile is one of the newest appellations in California, receiving American Viticultural Area status on April 29, 2002, the area has been referred to as Rockpile since the 1850s.
Located in northern Sonoma County, at the northwest corner of Dry Creek Valley, the Rockpile AVA encompasses nearly 15,000 acres, of which fewer than 160 are planted to vineyards. This makes Rockpile one of the smallest AVAs in the United States in terms of acreage planted.
Approximately 2,500 acres of the Rockpile AVA overlap the Dry Creek Valley viticultural area to the southeast. The vineyards range in elevation from 800 feet to nearly 2,100 feet.
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.
The predominant geographic highlight is that all vineyards must be at 800 feet elevation or above to qualify.
Though elevation falls into the geographic category, it also greatly affects the geology and climate. There are certain aspects that are true of all elevation-delineated AVAs, including poor soils, steep slopes, little water retention and great sun and wind exposures. With Rockpile, these aspects are exaggerated due to the lack of fog.
The lack of fog increases the amount of sun exposure, but decreases the amount of moisture available to the vines. The lack of moisture leads to smaller berries, loose bunches, little to no bunch rot or botrytis, and overall higher quality fruit.
The soils in the Rockpile AVA are very different from those of its neighboring viticultural areas. The primary differences are the extreme shallowness of the soils, the relative absence of silt or sand, higher oxidized iron properties, and the clay subsoil.
More than 95 percent of the vineyards in the Rockpile AVA are higher than 1,000 feet in elevation. This higher elevation, combined with the close proximity to the Pacific Ocean, creates unique climatic influences.
One of the under-appreciated characteristics is the wind. Rockpile receives the full force of the coastal breezes that typically sweep over the neighboring valleys. The winds stress the vines by further drying out what little water retention there may be in the soil, and they insure that there will be little or no rot in Rockpile fruit. This has the added bonus of limiting the need for herbicide and pesticide use in the vineyards.