Russian River Valley
Russian River Valley is named after the first non-native settlers of Sonoma County, the Russians. Their presence from 1812 to 1841, along the Sonoma coast, left a significant impact as they settled in the region to hunt sea otters and to provide food and staples to Russian colonies in Alaska. Agriculture, including viticulture, was a primary goal as well. Their first plantings at Fort Ross and subsequent vineyards in the Graton area and throughout west-central Sonoma County, were planted well before the Gold Rush of 1849. It is not known exactly when the they first planted grape vines, but it is believed that the early plantings at Fort Ross were the first in Sonoma County. The Russians summarily abandoned Northern California around 1841. Subsequent settlers, many immigrants from wine-producing European countries, continued the development of this viticultural venture.
Although the name Russian River Valley was not used on bottled wine until 1970, the area has a long tradition of winemaking. By 1876 viticulture was well-established in the Russian River Valley, when it was reported that the region produced in excess of 500,000 gallons of wine from about 7,000 planted acres. Some of the first in the region were The Santa Rosa Wine Company in 1876, Martini & Prati Winery in 1880, Korbel Champagne Cellars in 1882 and Foppiano Winery in 1896. The region became an official American Viticultural Area in 1983.
In October, 2005 an expansion of the Russian River Valley American Viticultural Area became law. This expansion increased the AVA total acreage by 30,200 acres to 126,600, of which approximately 15,000 total acres are planted to premium winegrapes. The amendment to the boundary lines follows the historically identifiable borders of the area influenced by cool, coastal fog.
The new boundary adds land to the east and south of the AVA's original established limits, including the entire Santa Rosa Plains, the entire Green Valley, Sonoma County region, and a southernmost region that is locally referred to as the Sebastopol Hills.
The Russian River Valley climate is influenced primarily by the regular intrusion of cooling fog from the Pacific Ocean a few miles to the west. Much like the tide, it ebbs and flows through the Petaluma Wind Gap and the channel cut by the Russian River through the coastal hills. The fog usually arrives in the evening, often dropping the temperature 35 to 40 degrees from its daytime high, and retreats to the ocean the following morning. This natural air-conditioning allows the grapes to develop full flavor maturity over an extended growing season, often 15 to 20 percent longer than neighboring areas, while retaining their all-important natural acidity.
The geologic history of the Russian River Valley is both active and recent. Several different events, some of which are ongoing, have shaped our topography and given rise to the multitude of soil types that occur in the region. The western-most portion of our county is bisected by the San Andreas Fault, a boundary between two tectonic plates, the Pacific and the North American. As the Pacific plate slides obliquely against the North American plate, it has created uplifting. In the western most part of the AVA the geologic formation that predominates is known as the Franciscan formation and consists of rocks that were jumbled and mixed in an Ocean trench far from here. The deposit was left at the edge of the North American plate as an ancient oceanic plate slid beneath it from 42-140 million years ago, now uplifted and eroded by wind and rain. The resulting soils are often quite rocky and well drained. About 3 to 5 milion years ago, volcanic eruptions from the Sonoma Volcanics to our immediate east deposited deep beds of volcanic ash on the shallow sea bottom. The resulting rock is known as the Wilson Grove Formation. Continued uplifting and the resultant erosion has given rise to a number of related soil types, with goldridge fine sandy loam being the primary type. It is extremely well drained. Erosion of the flanks of the volcanic vents formed much of the soil of the Santa Rosa plain. These soils tend to have a higher clay content, are shallow to very deep and vary in their drainage. Continued uplifting resulted in the Russian River changing course, cutting a path down the valley and across what are now the coastal hills, and leaving deep deposits of eroded material including beds of alluvial gravel, sand and clay in terraces along its course. These soils are also typically very well drained. Each of the various soil types has a sometimes subtle, sometimes profound effect on the grapes growing upon them.
