To Tame a Land — Louis L'Amour

By the time he was twenty, Rye Tyler had killed ten men. He had come west in a wagon train, seen the Indians kill his family and been left on his own in a harsh and wild country. From that brutal lesson Rye learned the harsh law of survival: the only friends he could trust were his rifle and his .44. His skill not only kept him alive, it made him a man to be feared. Then Rye met Liza, and there was a bright new light in his life -- a light a ruthless outlaw tried to steal away from him, sending Rye Tyler and his guns on their most savage death hunt.