There seems to be two kinds of Western (as in the Wild West) novels out there. First there is the modern western exemplified by Annie Proulx and Cormac McCarthy. Only you literature types need apply. Then there are the pulps set in the mythical Wild West. Most of these come close to the idea of speculative fiction as they usually deal with a history that is more in our minds then in reality. Lansdale's Blood Dance comfortably fits this category. He does a good job of mixing his usual crime noir/revenge style with the pulp excesses of the Western. He also throws in a few real-life figures for authenticity's sake; Wild Bill Hickok, Jack McCall (the man who killed Hickok), General Custer, and a lesser known but just as colorful legend, John "Liver-Eating" Johnson. Overall this novel is an entertaining read but not on par with Lansdale's thrillers and horror novels.
