The Upper Mississippi River Valley Viticultural Area was approved by the Federal Alcohol, Tobacco Tax and Trade Bureau, effective July 23, 2009. This is the largest American Viticultural Area (AVA) in the U.S. covering 29,914 square miles in Northeast Iowa, Southwest Minnesota, Northwest Illinois and Southwest Wisconsin.
Vineyards and wineries here operate among a unique geologic and topographic environment as defined by Major Land Resource Area 105 (MLRA 105) and the Driftless Area Initiative (DAI). While the MLRA expresses a rugged, bedrock controlled environment with soils lacking the glacial drift of areas outside the boundary, the DAI slightly extends the MLRA boundary in some areas to more fully capture included watersheds and transitional areas of increasing glacial drift.
MLRA’s are managed by the Natural Resources Conservation Service (NRCS) under the United States Department of Agriculture and are characterized by like-patterned soils, climate, water, and land uses usually over several thousand acres. The DAI was created and is managed by a joint venture of Resource Conservation and Development (RC&D) councils under the NRCS in the four-state Midwest Driftless Area. The DAI mandate is to conserve land, water and habitat resources that are heavily influenced by the dramatic landscape.
The Upper Mississippi River Valley AVA (UMRV) is distinguished as well as controlled by several components. Broad, well-defined watershed features are somewhat equidistant on both sides of the river. Exposed and near-the-surface bedrock supports high bluffs topography. Another component is the unique Paleozoic Plateau preserved when more recent glacial incursions strangely surrounded and bypassed the area. This atypical lack of glacial till is denoted by the Midwest Driftless Area.
The UMRV boundary, then, maintains surface topographies and subsurface structures that were not crushed or scraped smooth or their soils embedded with miscellaneous deposits as typical with areas outside the boundary. As such, the boundary involves steep-sided cliffs, bluffs, deeply entrenched stream valleys and Karst features. Overall, the area’s steep hills, ridges, and thinner glacial till facilitate better drainage for grapes than topographies outside the boundary. Topographies outside the boundary are dominated by smoother landforms of unconsolidated materials, or dissections of them, and are covered by thicker glacial drift and alluvium.
The major period of carving that would solidify today’s position of the upper Mississippi River Valley began 15,000 years ago. At that time, the massive Wisconsin Glacier with Minnesota and Iowa lobes began to melt and retreat into Canada. Not only did Glacial River Warren result from this melting to help create today’s upper Mississippi River Valley, so too did overflow from the vast Glacial Lake Agassiz. Lake Agassiz straddled areas of Canada and North America.
These water flows combined with those of the glacial St. Croix River already draining glacial Lake Duluth (Lake Superior). The relatively sediment-free waters of Lake Duluth helped carve the upper Mississippi River Valley to 250 meters in depth before alluvial deposits later began refilling the channel.
Warming temperatures not only brought glacial retreat to the area, but also humans around 9,000 years ago. Since that time, Native peoples had been successful inhabiting campsites and small villages along upper Mississippi River Valley tributaries, hills, and valleys. Watershed topographies on both sides of the river as well as more distinctive features of the Paleozoic Plateau provided ample cover for wildlife and therefore hunting.
Watershed features feeding the valley held many Native tribes including the Fox, Sac, Dakota, and Winnebago. Many others including the Potawatomi, Menominee, Chippewa, and Ottowa would travel to the area for trade and special gatherings.
Christopher Columbus likely noted on a map the mouth of the Mississippi River at the Gulf of Mexico in 1507, and Hernando DeSoto’s expedition in 1541 explored the river’s midsection. The first Europeans to discover the upper Mississippi River were Jacques Marquette and Louis Joliet. They entered the river’s upper portion June 17, 1673 serving as the first to more fully document and claim discovery of the UMRV AVA.
After subsequent incursions by Europeans, fur and lead mining industries more fully developed throughout the upper Mississippi River Valley. The Louisiana Purchase in 1803 and resolution of the Black Hawk War in 1832 enabled legal settlements on both sides of the river by those from the eastern United States. The river always had been used as a travel and trade route, and it soon began transporting cut logs for an emerging timber industry.
Today’s pronunciation of the Mississippi River emerged as eastern explorers attempted to enunciate Native American references to the Big River. The region’s native grape varieties added to a thriving grape and winemaking industry throughout the late 19th and early 20th centuries. In 1919, for example, Iowa ranked sixth in the nation in grape production and Illinois realized even higher production levels in some years.
However, the advent of Prohibition, some untimely freezes and droughts, and a regional redirection of crops into corn and soybeans weakened these totals. Finally, wind drift from introduction of the new corn herbicide 2,4-D severely crippled the regional grape industry.
Fortunately, improvements in commodity crop sprays paralleled regional cultivation of French-American hybrid grape varietals beginning the middle of the 20th century. These varietals were produced to combine winter hardiness with high disease resistance and excellent taste qualities. In the last 20 years, this improving environment for marketable grapes has provided renewed confidence for grape growers and winemakers throughout the region.
Since the early 1990s, the region has seen a vigorous return to grape and wine production using optimized French-American hybrid and other varietals. Today, the UMRV AVA boundary represents 32 wineries and 445 vineyard acres. Active programs and associations exist to help more wineries and vineyards to come on line.