The history of Sioux Falls revolves around the cascades of the Big Sioux River. The falls were created about 14,000 years ago during the last ice age. The lure of the falls has been a powerful influence. Ho-Chunk, Ioway, Otoe, Missouri, Omaha (and Ponca at the time), Quapaw, Kansa, Osage, Arikira, Dakota, and Cheyenne people inhabited and settled the region previous to Europeans and European descendants. Numerous burial mounds still exist on the high bluffs near the river and are spread throughout the general vicinity. Indigenous people maintained an agricultural society with fortified villages, and the later arrivals rebuilt on many of the same sites that were previously settled. Lakota populate urban and reservation communities in the contemporary state and many Lakota, Dakota, and numerous other Indigenous Americans reside in Sioux Falls today.