Blue Mounds State Park, named for a long, high Sioux quartzite cliff, is located in southwestern Minnesota on the Iowa and South Dakota borders. The cliff, one and one-half miles long and up to ninety feet high, appeared to be blue in color to the early Euro-American immigrants who saw it from a distance. A unique herd of bison, the largest North American mammal, makes its home in the park on 533 acres of native tall grass prairie, which escaped plowing due to poor soil quality.
Platteville limestone is a distinctive building stone of southeastern Minnesota and southwestern Wisconsin characterized by its gray color, rough texture, and many fossils. It was heavily used in the early decades of the building of the Twin Cities and Faribault.