What? Indian mounds are earthworks made by native peoples of the Woodland period (800 B.C. to the time of historic contact with European-Americans). Most Minnesota mounds are low, rounded masses of earth, standing 1 to 40 feet high and 5 feet to more than 150 feet wide. Mounds are usually found in groups ranging from two to more than 200. They can be as "new" as 600 years old, or as old as 2,500 years. Effigy mounds (in the shapes of insects or other animals) and pyramidal mounds are rare in Minnesota.
Who? Why? People once speculated that a vanished race of "mound builders" left these earthworks. But research by archaeologists and anthropologists has proven that the mounds were built by the ancestors of American Indians who live in Minnesota today. Mounds are most closely associated with ancestors of the Dakota people. Most of the earthworks were made for burials; some were constructed for other uses such as fortifications or platforms for dwellings.
Where? Indian mounds have been found across most of Minnesota, except for the Arrowhead region of Cook, Lake, and St. Louis counties. They were commonly built near deciduous forests and along rivers, streams, and lakes in places such as the Mille Lacs and Otter Tail regions, and along the Mississippi, Minnesota, and Cannon rivers.
How many? Archaeologists estimate that there were once 10,000 to 25,000 mounds in Minnesota. Today as many as 80 percent of the mounds are gone, due to losses from erosion, agriculture, road-building, and burrowing animals. The most destructive species has been human: Since the time of European contact, people have disrupted or looted Indian mounds—activities that are illegal under state and federal laws today.
Where can I visit? Grand Mound Historic Site near International Falls, site of the largest burial mound in the upper Midwest, has exhibits that describe the lives of the people who built the mounds there. Indian Mounds Park in St. Paul has a complex of large mounds on a bluff overlooking the Mississippi River and the city skyline. At Red Wing Archaeological Preserve, you can talk to archaeologists who are using state-of-the-art, noninvasive techniques to study a prehistoric village and rare flat-topped mound site. Some state parks contain Indian mounds: Itasca State Park has mounds at the Itasca Indian Cemetery, and Mille Lacs Kathio State Park’s 19 archaeological sites include burial mounds. Mounds are cemeteries and should be respected as such.
Thomas O’Sullivan, free-lance writer