Spirit Mound was a sacred place to area tribes long before the first settlers arrived from the east. To the Yankton Sioux, Omaha, Otoes, and other tribes, it was the mountain of little people. Indians believed it was bad medicine to see the Can O' ti la, or little people. A person who encountered one of them or was wounded by their arrows necessarily consulted a spiritual healer. If the person ignored this warning, he or she would face a serious problem or even death.