Minnesota River Prairie Trends

Prairies that once dominated the landscape—less than one percent remains
Prior to Euro-American settlement, more than 18 million acres of prairie covered Minnesota. Our prairie lands were part of the largest ecosystem in North America, which stretched from Canada to Mexico and from the Rockies to Indiana. A wealth of diverse species, habitats and cultures thrived here. At the time of Euro-American settlement, upland prairie spread across most of the land south and west of Mankato. Historically, fires burned annually over large areas of Southern Minnesota limiting freqency and location of trees (MCBS, 2007). The prairie landscape of the Midwest was one of our nation’s most diverse terrestrial ecosystems. Over 900 species of plants have been recorded on remaining prairies in Minnesota, with up to 300 or more species per individual prairie remnant. Almost half of Minnesota’s rare species are prairie plants and animals (DNR, 2008).
Conversion of Prairie to Cropland
Statewide, today only 180,000-200,000 acres of prairie remain compared to the 18 million acres of prairie prior to Euro-American settlement, In the Minnesota River Prairie subsection of the state (see map left area in yellow) DNR researchers estimated landscape change from 1890s to 1990s that shows the conversion from prairie to cropland (DNR, 2006).
  1890 1990
Prairie 77.6% 0.0%
Wetland Non-forest 13.0% 1.9%
Grassland   9%
Cropland   83.0%

“Prairie is rolling or gently undulating and bearing most everywhere an unusually healthy growth of grasses are auspicious [for settlers]...except for the entire want of timber.” —Public land surveyor David Watson describing the prairies in Swede Prairie Township of Yellow Medicine County in 1867 (MCBS, 2007).

The map above shows the small amount of native prairie that remains statewide. It depicts current native prairies documented by the DNR’s Minnesota County Biological Survey from 1987-2008 (shown in red), in comparison with the prairie vegetation recorded during the Public Land Survey from 1847-1908 (shown in yellow and tan). Less than 1 percent of the prairies recorded in Minnesota during the Public Land Survey remain (MCBS, 2009).

Learn more about Minnesota River Basin Trends