Which of these tribes were the most powerful in the missouri river valley during the 19th century?

Question

The Sioux, Arapaho, Nez Perce, Pueblo, or Apache?

Answer 1

Apache. No doubt. None of the others were from that area.

Answer 2

Well if you want to go by battles, the Sioux, with the help of the Northern Cheyenne, defeated Custer at the Little Big Horn. Some of the most notable Indian warriors and leaders were Sioux, Crazy Horse, and Sitting Bull. The Sioux Nation is very much apart of the Missouri River Valley and it's history.