As to the introduction of a lone Indian (who looks well past his sell by date) to liven up the plot... Sorry it lost me there too! Ok there are great examples of race and gender politics but it's so obvious. It's got great actors but not one of them is fleshed out as a character you can get into.
And finally and bizarrely for a movie set in the desolate plains, the movie is filmed in some odd square cinematography (unless the Phoenix had an aberrations. Not one to remember is the best I can say.