This large, 329,000-acre catch-all AVA includes just about all of Sonoma County, including the smaller AVAs within it, except for its southernmost appellations (Sonoma Valley and Carneros). BATF regulations require ‘estate-bottled’ wines to be produced and bottled in the same viticultural area as the vineyards where the grapes were grown. Thus, this broad and loose AVA boundary is convenient for producers with vineyards scattered through the county who wish to use an AVA designation, rather than the more generic ‘Sonoma County’ appellation. The most notable example of such a producer is, of course, the largest vineyard owner in the county, Gallo of Sonoma. Not surprisingly, they were the main petitioners for the Northern Sonoma AVA.