William Faw Faw or Wawasi. The Otoe were once part of the Siouan tribes of the Great Lakes region, a group commonly known as the Winnebago. A large group split off and began to migrate to the South and West. This group split again, forming at least three distinct tribes: the Ioway, Missouria and the Otoe. The latter settled in the lower Nemaha River valley. They adopted the horse culture and semi-nomadic lifestyle of the Great Plains, making the buffalo central to their diet and culture.