Ralph Compton, The convict trail

As he transports six cold-blooded convicts across hard country, Deputy Marshal Logan Kane has to be prepared for anything. Even with the hard cages cased in his prison wagon, Kane needs to watch his back and keep his colt close at hand. There are rustlers, lynch mobs, and three brothers from a New Orleans gang, not to mention the convicts' cronies, who are looking to bust them loose.
Kane is on the lookout for danger every waking moment, and his sleep is haunted by demons of his past. If he wants to keep this ride from being his last, he'll have to take on all corners and learn to deal with what can't be changed.