What was the first American Viticultural Area (AVA) in California and when was it established?

C.

The first AVA in California was Napa Valley, established in February 1981. According to the Wine Institute, other California winegrowing regions that were established later that same year include: Santa Maria Valley in San Luis Obispo and Santa Barbara Counties, San Pasqual Valley in San Diego County, and Guenoc Valley in Lake County.