When The Lewis and Clark expedition started coming up the Missouri, they heard about a mound that was said to be occupied by evil spirits. It was called the Hill of the Little Devils. The Oto Native Americans warned them to stay away. However, like typical adventurers, that caused them to be sure to find out where it was and how to get there. On August 25, 1804, a group of them including York, Clark’s slave, and Seaman, their dog, started out crossing the level prairie and walked to the Mound. The left the Vermilion River (then called the White Stone River) at 8:00 am and arrived at 12:00, approximately a nine-mile walk. It was a very hot day and Seaman soon became too hot and so was taken back to the river. They did not see any spirits but they did see a beautiful prairie with large herds of buffalo (sic, bison) flocks of birds, swarms of insects, some of the biting kind. That is the Spirit Mound we see today, except, no buffalo (sic, bison).
FIRST LEGEND
Once a few Natives killed more game than was necessary and they left what they did not need to rot on the prairies. The Chief, outraged by their actions, instructed the medicine man to punish the offenders, and he did so by changing them into tiny spirits and ordering them to guard the wild game eternally from needless slaughter.
SECOND LEGEND
The second legend told of a tribe living near the Mound who had several lazy men who refused to hunt. Again, the chief instructed the medicine man to punish the offenders , and he did so by making them small spirits. He also doomed them to lie forever on the hill.