Question: This group of natives in North America were indigenous to the Interior Plains, historically nomadic, and relied on bison hunting.
Sentence (from "Cow Creek (Montana)"): During the steamboat era on the Missouri River, when low water prevented riverboats getting up to Fort Benton, the mouth of Cow Creek became a river landing and freighting depot, and it was the start of the Cow Island Trail by which freight was moved on to Fort Benton by going north up Cow Creek and then west.
Relevant evidence: No