The Alcohol and Tobacco Tax and Trade Bureau (TTB) establishes the approximately 306,650-acre Lewis-Clark Valley viticultural area in portions of Nez Perce, Lewis, Clearwater, and Latah Counties in Idaho and Asotin, Garfield, and Whitman Counties in Washington. TTB is also modifying the boundary of the existing Columbia Valley viticultural area to eliminate a partial overlap with the Lewis-Clark Valley viticultural area. The boundary modification will decrease the size of the approximately 11,370,320-acre Columbia Valley viticultural area by approximately 57,020 acres. The Lewis-Clark Valley viticultural area is not located within and does not overlap any other 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.