An AVA is an American Viticultural Area that has been recognized by the federal government for a distinctive combination of soil, climate, and identifiable regional wine character. AVAs are often referred to as appellations or districts, such as the Napa Valley appellation. These laws are meant to ensure quality within specific regions and to establish consistency in the product.
The AVA is used on wine labels to indicate region of origin. To be eligible to use a specific AVA designation, 85% of the grapes used in the wine must be grown in the AVA itself. They are decided from geography rather than state line because within one state there can be many different types of climates and terroirs, each creating vastly different wines.