Twenty are conical, one flat-topped and one elongated, all near Otter Tail Lake.
The mound group has the oldest radiocarbon date of any in present-day Minnesota.
[3] Its construction is similar to others in the area, suggesting they were all built by members of the same tribe over a period of time.
Similarities include a central burial pit, covered by logs, and a possibly crematory.
This article about a property in Minnesota on the National Register of Historic Places is a stub.