I love it when counties place markers at their historic sites! I always stop to see what little nuggets of history are being dropped. This historic marker near Green Lake in Kandiyohi County, Minnesota explains:
“During the Woodland period, about 1000 B.C. to A.D. 1650, Indian peoples began constructing earthworks or “mounds.” Many if not most of these mounds functioned to visibly define and demarcate burial areas, much as headstones do today. This mound complex is about 50 acres in size. It is located one-half mile south of the Green Lake outlet, and extends one-quarter mile inland from the eastern shore. Erosion, cultivation, and construction have reduced the height of the mounds so they are barely visible. State law protects Indian mounds, like all human burial grounds, from unauthorized disturbances.”
I did see what was likely a few small mounds on private property to the east of this marker, but the long grass made them hard to photograph from the road. The rest have probably been lost 
