This interactive map is excellent for getting to the specific tribes of areas, https://native-land.ca/.

When you search for Yellowstone it names and hyperlinks to their info pages of the 4 tribes which sites resources and links to the tribes websites, if there is one. I know for where I live, the local tribal websites are a trove of amazing information of their history as a tribe and anout the land itself.

The 4 tribes linked:

• Newe Sogobia (Eastern Shoshone)

• Cayuse, Umatilla and Walla Walla

• Apsáalooke (Crow)

• Tséstho’e (Cheyenne)