I thought the link below was interesting reading.
It is relative. There is said, that most Westerns deal with the civil war. But what about especially Zapata westerns? These are westerns, too, aren’t they?
And the Klondike and Alaska should be considered, I think “Death Hunt” with Charles Bronson and Lee Marvin a Western.
As I’ve said many times, the western is not just a plave but a feel and theme. That is why Man Pride and Vengeance [b]IS[b] a western. Same goes for The Three Burials of Melquidas Estrada, and the Proposition.