A series of 19 mounds overlook the Des Moines River in the northwest section of the park. These were built by an ancient group of Woodland Culture Indians in order to bury their dead. Such mounds are usually found on hilltops overlooking river valleys. These are sacred locations to living Native American peoples - please pay your respects and avoid walking on or otherwise disturbing the mounds. The following link is about the Woodland Culture. Woodland (off-site) The following link is to OSA's Burials Program main page; from here there are many links to specific information: OSA Burials Program. (off-site) the following link allows access to Iowa's archaeological site location information as counts by one mile section: Archaeological sites.