Within the four-state area included in the new AVA is the grand Chateau St. Croix Winery & Vineyards in St. Croix, Wisc.
Washington, D.C.--Effective July 22, 2009, the United States will have its largest AVA covering 29,914 square miles in parts of four states. The Upper Mississippi River Valley Viticultural Area just approved by the TTB averages 120 miles from east to west and 225 miles from north to south in southeastern Minnesota, southwest Wisconsin, northwest Illinois and northeast Iowa.
Map of the AVA boundaries, from the Limestone Bluffs RC&D.
The Upper Mississippi River Valley AVA Committee chaired by Warren Johnson, now retired, of the Limestone Bluffs RC&D (Resource Conservation and Development) in Maquoketa, Iowa submitted the petition requesting the new appellation. The initial grant funds to start the application process came from the Iowa State University Leopold Center. Representatives of the four states involved began working on the project in 2006; the staff at Limestone Bluffs did much of the groundwork on the project, and the petition was filed late in 2006.
The Wisconsin ice age and the effects of glaciation on the region provided the basis for most of the distinguishing features required to establish an AVA. The upper Mississippi river valley was a driftless area, meaning that the massive Wisconsin glacier did not actually cover the AVA, although its lobes extended into Minnesota and Iowa.
When the glacier started retreating some 15,000 years ago, the resulting glacial water flows combined with the glacial St. Croix River and what is now Lake Superior. The relatively sediment-free drainage helped carve the channel to a depth of about 820 feet, and eventually alluvial deposits refilled the channel.
Consequently, the topography does not have substantial amounts of materials deposited by glaciers. The boundaries of the AVA divide the bedrock-controlled landscapes of the AVA from the gently rolling landscapes and glaciated erosional surfaces that are outside the valley.
A foggy morning at St. Croix Vineyards in Stillwater, Minn.
Historically, the combination of microclimates and diverse settings have supported flora and fauna not found outside the boundary of the AVA. Native American grape varieties thrived in the AVA during the late 19th and early 20th centuries, but the viticulture based on native grapes declined as a result of Prohibition and other factors.
Later in the 20th century, the introduction of disease- and cold-resistant French hybrids and other hybrids developed in the region. Spray improvements restored confidence in grapegrowing as an industry in the AVA.
Within the Upper Mississippi River Valley Viticultural Area is the Lake Wisconsin AVA established in 1994. This appellation consists of 43.75 square miles in Columbia and Dane Counties, Wisc. While it has some of the same geographical features as the new AVA, it is recognized as a transitional zone from unglaciated to glaciated topography. TTB determined that despite some of the same characteristics, the differences justified the continued recognition of the Lake Wisconsin AVA as a distinct viticultural area within the Upper Mississippi River Valley AVA.
According to the TTB, only one comment was received during the period of time open for comment from the public, and that was a favorable one from Bill Northey, Iowa's Secretary of Agriculture. Northey stated that "This designation will allow vintners and grapegrowers within the region's boundaries to better describe the origin of their wines and grapes, and permit consumers the opportunity to better identify wines they may purchase from that unique area."
