The Bounty Hunters — Elmore Leonard

The old Apache renegade Soldado Viejo is hiding out in Mexico, and the Arizona Department Adjutant has selected two men to hunt him down. One--Dave Flynn--knows war, the land, and the nature of his prey. The other is a kid lieutenant named Bowers. But there's a different kind of war happening in Soyopa. And if Flynn and his young associate choose the wrong allies--and the wrong enemy--they won't be getting out alive.