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.
Located on 1,830 acres, the park is in an area known as Coteau des Prairies (in English, a hilly prairie upland). As high as 2,000 feet above sea level, the plateau runs from southeast North Dakota, through southwest Minnesota, and into northwestern Iowa. Dating to 1,700 million years ago, numerous Sioux quartzite outcrops and boulders, colored pink, red, white, and purple, can be seen in the fields.
The old quartzite quarries in the park were owned and operated by the Luverne Granite Company. The stone was used to construct many local buildings, such as the Rock County Courthouse (1882), the old city hall (ca. 1890s), Trinity Episcopal Church (1891), and the Hinkly House in Luverne (1892).
Before white immigrants came, the eastern cougar, elk, pronghorn antelope, grizzly bear, bison, prairie dog, and prairie chicken all inhabited the southwestern Minnesota prairie. Because of habitat changes caused by settlement, only bison, commonly known as buffalo, now live in the park.
In 1961, the current herd of North American plains bison (scientific name Bison bison) began when three bison were relocated from the Fort Niobrara Wildlife Refuge near Valentine, Nebraska, to the park. Many of the bison in commercial herds in the United States carry cattle genes; however, DNA testing, using blood and tail hair, shows that the Blue Mounds herd is among the most genetically pure in the country. To promote healthy herds, increase genetic diversity, and prevent inbreeding, park staff participate in a national conservation program that exchanges bison among pure herds. The pasture in the park can sustain about seventy-five mature animals, and park visitors can view them from an observation platform.
Running across 1,250 feet on top of the Blue Mound is a mysterious wall—as much as five feet in height in some places—composed of rocks and small-to-huge boulders. The sunrise and sunset on the spring and fall equinox closely align with the wall’s east-west orientation. Theories about the wall’s origin and purpose include that it was an early white-immigrant-constructed wall; a Minnesota equivalent of England’s Stonehenge; and a barrier to help Indians stampede bison off the cliff during hunts. Surveys and excavation of the wall in the 1980s, however, concluded that the wall was built after the mid 1800’s. In the 2010s, the issue remains unresolved.
Beginning in 1938, workers in the WPA (Works Progress Administration) built five structures in the park: a latrine and the upper and lower dams on Mound Creek, which created Upper and Lower Mound Lakes. The rustic style of the structures features native materials such as locally quarried quartzite. Rustic-style architecture, as defined by the National Park Service, is labor intensive, finely crafted, and uniquely American.
The Upper and Lower Mound Lakes were once the only lakes in Rock County. In 2014, over eleven inches of rain destroyed the lower dam. This caused Lower Mound Lake — then the only recreational lake in Rock County — to drain. In 2016, the Minnesota Department of Natural Resources decided not to make repairs to the dam that would have restored Lower Mound Lake.
Visitors to the park enjoy hiking on three main trails, biking, rock climbing, spotting bison, camping, birding, and exploring for flora and fauna. Campers can spend the night in a tipi and snowmobile in the winter. Native prickly pear cactus grows in the quartzite outcrops, and birders may spot the uncommon blue grosbeak. Mound Creek is home to the Topeka Shiner (Notropis tristis), a small minnow that is on the U.S. Fish and Wild Life Service’s endangered species list. The park is the only place in Minnesota where the lined snake (Tropidoclonion lineatum) is found.
For more information on this topic, check out the original entry on MNopedia.