A work in progress. These mounds were almost entirely obliterated by farming activities, a common occurrence. Archeological investigations have determined the shape and location of this set of circular and square earth structures, which were once 20 feet tall, and site workers mow the prairie to show the visitor the outlines of these huge patterns. From the parking lot, follow the signs to get you going in the right direction. The signs soon go away, but hike up the small hill towards the RR tracks, cross the farm access road and hike another 1000 or so feet to a circular arrangement of large stones (put there by the park staff). From this location you can look out and see the entire site. You are allowed to then walk down and traverse the mown paths. Everything is the honor system as there is no staff present. The day I was there, I was the only person.