Upper Mississippi River Valley AVA

Upper Mississippi River Valley is an American Viticultural Area (AVA) encompassing 29,914 square miles (77,480 km²; 19,145,000 acres) along the Upper Mississippi River and its tributaries located in northwest Illinois, northeast Iowa, southeast Minnesota and southwest Wisconsin. It was established on July 21, 2009, as, currently, the nation's largest viticultural area, by the Alcohol and Tobacco Tax and Trade Bureau (TTB), Treasury after reviewing the petition submitted by the Upper Mississippi River Valley AVA Committee on behalf of local vintners proposing a viticultural area named "Upper Mississippi River Valley." The area is 50 times larger than the Bordeaux wine regions of France. The climate of the Upper Mississippi Valley is continental and cool. The rolling hills and sloping landscape of the region permits maximum sun exposure which facilitates grape growth. Vineyards are planted in soils composed of mainly clay and silt loam on top of bedrock of limestone. The hardiness zone varies within the large north-to-south range from 5a to 6a.

The Lake Wisconsin viticultural area, established in 1994, contains some geographical features similar to those of the AVA, such as annual average frost-free period, elevation, and a mean precipitation of 29 in (740 mm), just 1 inch less than that of the Upper Mississippi River Valley AVA. At the same time, the Lake Wisconsin AVA is recognized as benefiting from the microclimate effects of the lower Wisconsin River Valley. The river moderates winter temperatures and air circulation within the river valley and helps prevent cold air accumulation and frost pockets from forming in the vineyards. In the summer, the river valley and limestone bluffs along the river's edge serve to channel air currents and increase air circulation, thus protecting the vineyards from mildew and rot in hot, humid weather. Additionally, the Lake Wisconsin AVA is recognized as a transitional zone from unglaciated to glaciated topography, and the soils within the Lake Wisconsin AVA contain some glacial till. Accordingly, although the Lake Wisconsin viticultural area shares some of the characteristics of the AVA, TTB believes that the differences justify the continued recognition of Lake Wisconsin as a distinct viticultural area within the proposed Upper Mississippi River Valley viticultural area.