The 11,075 acres (17 sq mi) area was established on December 13, 2011 by the Alcohol and Tobacco Tax and Trade Bureau (TTB), Treasury after reviewing the petition submitted by Thomas Farella of Farella-Park Vineyards and Bradford Kitson, on behalf of the vintners and grape growers in the Coombsville region of Napa Valley, proposing the viticultural area named "Coombsville.

"[4] The appellation is nestled in the southeastern region of the Napa Valley viticultural area, between the eastern shores of both the Napa River and Milliken Creek and the western ridgeline of the Vaca Range at the Solano County line.

Proximity to San Pablo Bay contributes to the temperate climate of Coombsville where the cool marine air and fog occurs almost daily during the growing season, arriving early and linger longer in the southern region of Napa Valley.

The Coombsville soils are dominated by the volcanic, rhyolitic tuff sedimentary rock and lava flows of the Vaca Range on the eastern side of the Napa Valley.

The area was the 16th sub-appellation designated within the 120,000 acres (188 sq mi) of Napa Valley AVA.