In this case I think the word "tribe" is referring to the Ute Mountain sub-group of the Ute people. But it's certainly nothing like the primitive society you a

In this case I think the word "tribe" is referring to the Ute Mountain sub-group of the Ute people. But it's certainly nothing like the primitive society you are imagining, and that's partly why I think a lot of American Indian nations don't use that word to describe themselves. For example, the "Seneca tribe" calls themselves the Seneca Nation. That is, they were and are a group of people sharing common ethnicity, culture, language, and some kind of governmental organization across their territory, which at one point covered a large portion of what is now western New York state. They lived in towns with palisade walls and farmed several crops. They interacted with other nations in a complicated geopolitical system involving trade, alliance, and war. It's a far cry from the image of dumb savages in crude huts. In the USA today, American Indian nations are essentially sovereign nations, and have some of their own territory in areas called reservations. So that's what we are talking about here: the actions of a sovereign nation, with its own government and geographical territory.