American Viticultural Area

An American Viticultural Area (AVA) is a designated wine grape-growing region in the United States, providing an official appellation for the mutual benefit of wineries and consumers. Winemakers frequently want their consumers to know about the geographic pedigree of their wines, as wines from a particular area can possess distinctive characteristics. Consumers often seek out wines from specific AVAs, and certain wines of particular pedigrees can claim premium prices and loyal customers. If a wine is labeled with an AVA, at least 85% of the grapes that make up the wine must have been grown in the AVA, and the wine must be fully finished in the state where the AVA is located.
Regulations.
The boundaries of AVAs are defined by the Tax and Trade Bureau (TTB), a component of the United States Department of the Treasury. The TTB defines AVAs at the request of wineries and other petitioners.
Section 4.25(e)(2) of the TTB regulations (27 C.F.R. § 4.25(e)(2)) outlines the procedure for proposing an AVA and provides that any interested party may petition the TTB to establish a grape-growing region as an AVA. Section 9.12 of the TTB regulations (27 C.F.R. § 9.12) prescribes the standards for petitions for the establishment or modification of AVAs. Petitions to establish an AVA must include the following: 
Once a petition is accepted as complete, the TTB may choose to seek public input on the proposal and at its sole discretion may approve the proposed AVA. 
Before the AVA system, wine appellations of origin in the United States were designated based on state or county boundaries. All of these appellations were grandfathered into federal regulations and may appear on wine labels as designated places of origin in lieu of an AVA, such as Sonoma County. In order for a wine to be labeled with a state or county appellation, at least 75% of the grapes used to make the wine must have been grown within the boundary of the appellation, and the wine must be fully finished within the state in which the appellation is located. Some states have more stringent rules, such as California, which requires 100% of the grapes used to make the wine be from California and that the wine be fully finished within the state. Washington requires 95% of the grapes in a Washington wine be grown in Washington.
Around the United States.
AVAs vary widely in size, ranging from the Upper Mississippi River Valley AVA, at more than 19 million acres () across four states (Illinois, Iowa, Minnesota, and Wisconsin), to the Cole Ranch AVA in Mendocino County, California, at only . The Augusta AVA, which occupies the area around the town of Augusta, Missouri, was the first recognized AVA, gaining the status on June 20, 1980. The second established AVA was Sonoma Valley, which was established in 1981. There are currently 252 AVAs in 33 states. Over half (141) of the AVAs are in California; Sonoma County alone contains 17 AVAs.
An AVA may be located within one or more larger AVAs. For example, the Santa Clara Valley AVA and Livermore Valley AVA are located within the territory of the San Francisco Bay AVA, which is itself located within the Central Coast AVA. In such cases, the wine may be labeled with any of the relevant AVAs, but winemakers generally label wines with the most specific AVA allowed for each wine. Smaller AVAs are often perceived to be associated with smaller production and higher quality wines, though this is not always the case. See map on the right showing the outline of the Paso Robles AVA (California's largest in terms of area), and the different AVAs that are contained within this large AVA. 
In 2018, the second session of the 115th Congress recognized the contribution of American Viticultural Areas to the economy. The Blunt-Merkley Resolution passed unanimously. It noted that an AVA allows vintners to describe more accurately the origin of their wine, while helping vintners to build and enhance the reputation and value of the wines produced. AVAs also allow consumers to attribute a given quality, reputation, or other characteristic to a wine made from grapes grown in an AVA. AVAs also help consumers identify what they purchase.
Viticultural areas and appellations in other countries.
Major wine growing countries such as France, Italy, and Spain have their own designations of viticultural areas and appellations. France has a system to identify the geographic origin of wines called the Appellation d’Origine Contrôlée/Protégée (AOC/AOP) that began in 1937. Italy uses the Denominazione di Origine Controllata (DOC) and Denominazione di Origine Controllata e Garantita (DOCG) system, which was first established in 1963. Today there are 329 different DOCs and 73 DOCGs in Italy. In Spain, the denominación de origen (DO) or denominación de origen protegida (DOP) system is used. Spain currently has 79 DOP’s, 2 DOC’s, 17 Vino de Pagos (VT), and 46 Vino de la Tierra (VdlT/IGP).