I really really want to love the Old West as a setting. It's so romantic: hard, lonely men and women wresting a living from a hard, lonely land under a huge, lonely sky. It's a place and time where you can't rely on anyone but yourself: lawmen, lovers, and old old friends will all turn on you in a second if the price is right. If your wits are sharp and your hands are fast, you might just make your fortune...but the only guaranteed payday is the undertaker's.
Problem is, all that romance is inextricably tied to the genocide of the Native Americans. The only reason that big empty land is so empty is that the army--and the plagues that preceded them--came through and emptied it. There's no getting around it. If the story has no natives, it's another entry in the long list of American cultural works that pretend the genocide never happened. If it treats the natives as unfathomable, implacable enemies, it plays the same notes that made the genocide possible in the first place. Similarly, Tonto-like sidekicks turn a a civilization and culture into a one-dimensional caricature. Few and far between are the stories that manage to use a Western setting in a responsible way.
I recently finished The Incorruptibles, by John Hornor Jacobs. I'm sorry to say that it makes the Native Americans into terrible creatures, ones with whom there is no possibility of dialogue or compromise.