Viticulture has been an integral part of [Sonoma County’s](/county/sonoma-county) history and the Russian River region is no exception. The first vines were planted here by European immigrants in the mid-nineteenth century closely followed by the first commercial wineries, but the region's wine industry was hit hard by the onset of Prohibition in 1920 and few cellars survived its thirteen year restriction. The last half century however, has seen a reversal of fortune for grape growers and winemakers across [California](/region/california). From the 1970s onwards, producers in the Russian River Valley have focussed on high quality, premium grapes, and wines which express the subtle nuances of their terroir, building a reputation as one of the nation's - perhaps the world's - most prestigious wine-growing regions. Typical [Burgundy](/region/burgundy) varieties, [Chardonnay](/chardonnay) and [Pinot Noir](/pinot-noir) together make up around 70% of all plantings within the appellation, producing still and sparkling wines of distinction. [Zinfandel](/zinfandel) is a clear third in order of vine share, with [Cabernet Sauvignon](/cabernet-sauvignon), [Merlot](/merlot) and [Sauvignon Blanc](/sauvignon-blanc) also well represented in Russian River Valley’s vineyards. However, such is the diversity here, a large number of other varieties have been found to thrive. These include [Syrah](/syrah), [Sangiovese](/sangiovese), [Pinot Gris](/pinot-gris) and [Gewürztraminer](/gewurztraminer) amongst many others. The climate of the AVA is heavily influenced by the river from which it takes its name and the Pacific fog which penetrates through the Petaluma gap creating a significant diurnal temperature variation. This natural advantage affords the fruits grown here, the luxury of a climate that is cool - but not cold, and an extended growing season that allows the grapes to develop complexity without losing their freshness or acidity. Of course various microclimates within the bounds of the AVA lend themselves to the preferences of particular varieties. Typically, the coolest, foggiest regions are in the south and west of the appellation where [Chardonnay](/chardonnay) and [Pinot Noir](/pinot-noir) reign supreme, whilst the northeast is noticeably warmer and sees the chief red grape replaced by [Bordeaux](/region/bordeaux) varieties [Cabernet Sauvignon](/cabernet-sauvignon) and [Merlot](/merlot). A variety of soil types across the appellation range from the most prominent and distinctive, Goldridge - a fine, sandy loam, to alluvial and clay soils. Today, Russian River Valley AVA boasts six-thousand vineyard hectares, around seventy wineries and a reputation for viticultural excellence. It's cool climate grapes are sought by some of the state's most acclaimed wineries, and its wines - particularly its buttery [Chardonnay](/chardonnay) varietals and elegant, rich [Pinot Noirs](/pinot-noir) - command huge respect amongst consumers, critics and collectors.