Where did the plains Indians originate from

The Plains Indians originated from the Great Plains and the Canadian Prairies. However, it is important to note that all of this prairie land stretches from Canada, to the United States and down to Mexico. It touches the following provinces of Canada: Alberta, Manitoba and Saskatchewan. The states it has land in are Colorado, Kansas, Montana, Nebraska, New Mexico, North Dakota, Oklahoma, South Dakota, Texas and Wyoming. In Mexico, it touches some territory in northern Mexico, but stops at the Rio Grande.