The Alcohol and Tobacco Tax and Trade Bureau (TTB) establishes the approximately 202,476-acre "Petaluma Gap" viticultural area in portions of Sonoma and Marin Counties in California. The viticultural area lies entirely within the larger existing North Coast viticultural area and partially within the established Sonoma Coast viticultural area. TTB also modifies the boundary of the North Coast viticultural area to eliminate a partial overlap with the Petaluma Gap viticultural area. TTB designates viticultural areas to allow vintners to better describe the origin of their wines and to allow consumers to better identify wines they may purchase.