olive notes while Napa County Cabernets are characterized by their strong black fruit flavours. In California, the main stylistic difference in Cabernet Sauvignon is between hillside/mountain vineyards and those on flatter terrains like valley floors or some areas of the Central Valley. In Napa, the hillside vineyards of Diamond Mountain District, Howell Mountain, Mt. Veeder, Spring Mountain District have thinner, less fertile soils, which produce smaller berries with more intense flavours, reminiscent of Bordeaux wines that require years of ageing to mature. The yields are also much lower, typically in the range of 1–2 tons per acre in contrast to the 4–8 tons that can be produced in the more fertile valley floors. Wines produced from mountainside vineyards tend to be characterized by deep inky colours and strong berry aromas. Throughout California, many wine regions have the potential to grow Cabernet Sauvignon to full ripeness and produce fruity, full-bodied wines with alcohol levels regularly above the Bordeaux average of 12–13%—often in excess of 14%. The use of oak in California Cabernet has a long history, with many producers favouring the use of new oak barrels heavily composed of American oak. After the early 1980s' unsuccessful trend to create more "food friendly" wines with less ripeness and less oak influence, winemakers' focus shifted back to oak influence. Still, producers were more inclined to limit and lighten the use of oak barrels, with many turning to French oak or a combination of new and older oak barrels. Washington State According to the Washington State Wine Commission, Cabernet Sauvignon is the most widely planted red grape variety in Washington state. It is generally found in the warmer sites of the Columbia Valley. The vines are choice plantings for growers due to their hardy vine stalks and resistance to the cold winter frost that is commonplace in Eastern Washington. Washington Cabernet Sauvignon is characterized by its fruitiness and easy drinking styles that are not overly tannic. Recent Washington American Viticultural Areas (AVAs) that have seen some success with their Cabernet Sauvignons include Red Mountain, Walla Walla Valley and parts of the Yakima Valley AVA near the Tri-Cities region. Elsewhere in the United States In Oregon, there are small quantities of Cabernet Sauvignon planted in the warmer southern regions of the Umpqua and Rogue Valleys. It has also started to develop a presence in the Arizona, New York, Ohio, Texas and Virginia wine industries, particularly