This relatively young appellation is often spoken of in conjunction with its neighbour, [Big Valley](/ava/big-valley-district-ava), and the two areas share a number of milestone dates, climatic conditions and a broadly similar range of grape varieties. Kelsey Bench and [Big Valley](/ava/big-valley-district-ava) petitioned for AVA status together, and both made adjustments to their boundaries to accommodate the other. Since designation was granted, the two have grown in reputation as sources of superb fruit and subsequent fine wines. The Mayacama Mountains and the proximity of Clear Lake influence conditions in both of these AVAs. Kelsey Bench is further from the water’s direct temperature moderating impact, however the cool breezes coming down over the mountain ridges create a similar tempering effect and hence, the grapes here enjoy the same benefits of an extended growing season. Perhaps the most important factor in Kelsey Bench AVA though is the elevation. Vineyards occupy sites up to five-hundred metres above sea level with a mostly northeastern exposure. This elevation is a little higher than [Big Valley](/ava/big-valley-district-ava), and subsequently the daytime temperatures here are a degree or two warmer, but not as warm as [Red Hills AVA](/ava/red-hills-ava) to the east. The increased altitude ensures a wide variation in temperature between day and night, allowing grapes to ripen slowly and thus achieve a balance of fruit flavours and acidity. Rich, volcanic soils - red in colour - complete the area’s distinctive terroir. In addition to the principal varieties of [Sauvignon Blanc](/sauvignon-blanc), [Cabernet Franc](/cabernet-franc) and [Zinfandel](/zinfandel), [Chardonnay](/chardonnay), [Viognier](/viognier) and even some [Riesling](/riesling) have found success in the vineyards of Kelsey Bench AVA.