Capay Valley is an American Viticultural Area (AVA) situated in the landform, Capay Valley, in northwestern Yolo County of Northern California. The wine appellation was established on December 20, 2002 as the nation's 147th, the state's 85th and the county's fourth AVA by the Bureau of Alcohol, Tobacco and Firearms (ATF), Treasury after reviewing the petition from Tom Frederick and Pam Welch of Capay Valley Vineyards proposing a viticultural area in Yolo County known as "Capay Valley."