Calistoga, in Napa valley, has been recognised an officially as an American Viticultural Area (AVA)
The US Department of Treasury’s Alcohol Tax and Trade Bureau has approved the designation after years of representations.
Linda Reiff, executive director of Napa Valley Vintners, the association that represents 375 Napa wineries, said: "We could not have achieved this incredible victory for wine consumers and the wine industry had it not been for Congressman Mike Thompson, who worked tirelessly to ensure truth-in-wine-labeling for consumers and intimately understands the need for forthright protection of wine's place of origin."
According to the association, there has been an increase in the number of wine producers using the Calistoga name falsely in their brand labeling.