Long Valley-Lake County is an American Viticultural Area (AVA) located in the eastern part of Lake County, California, established in April 2023 and encompassing 7,605 acres (30.78 km2).
Lake deposits form a soil composed of "tuffaceous and diatomaceous sands and silts, limestone, gravel, and intercalated volcanic rocks".
[1] Categorized as a Region III on the Winkler scale, Long Valley's annual recorded rainfall is similar to other Lake County AVAs, between 27 inches (690 mm) and 33 inches (840 mm), increasing as one moves west.
Winds blowing through the valley during the growing season cool the vines from the day's heat.
[1] Cache Creek Vineyards, which is based at the southern tip of Long Valley, and Shannon Family of Wines, which in 2015 acquired 280 acres in the area,[2] were key petitioners to get the region recognized as an American Viticultural Area.