American Viticultural Area (AVA)
An American Vicitultural Area (AVA) is a specially designated wine grape-growing region in the United States.
AVAs are assigned according to specific geographical features and boundaries by the Alcohol and Tobacco Tax and Trade Bureau, and unlike most European appellations of origin, an AVA specifies only a geographical location from which at least 85% of the grapes used to make wine must have been grown (if that AVA is stated on the wine bottle label).
AVAs do not restrict the number of allowable grape varieties to be grown, winemaking methods, or crop yield.
As of October 2013 there are 218 AVAs.
Requirements to become an AVA include evidence that the name is locally or nationally known referring to the area, historical or current evidence that the boundaries are legitimate, and evidence that the growing conditions such as climate, soil, elevation and physical features are distinctive.