BOISE -- It may not be the Napa Valley yet, but Idaho's burgeoning wine-growing region is unique, according to the federal government.

The Department of the Treasury on Friday declared 8,263 square miles of southwest Idaho and southeast Oregon an American Viticultural Area.

The designation is for grape growing regions that produce wines with a distinctive style and taste, stemming from factors ranging from climate to soil composition to geography.

The Snake River Valley is the first AVA for Idaho's growing wine industry, and will encompass 15 wineries, 46 vineyards and 1,107 acres. It will stretch from Twin Falls into Oregon.

The Idaho Grape Growers and Wine Producers Commission requested designation as an AVA in 2005.

So far, 172 areas have been designated in the United States, 93 of them in California. The largest is the 26,000 Ohio River Valley AVA.