The Shadow of Valko — Michael D. George

The Valko Kid felt one of the posse's bullets ripping through his flesh. Wounded, he managed to ride on, with only willpower keeping him in his saddle. But he is confronted by a female sheriff and collapses at her feet. Slung into jail, Valko hears the sound of a gallows being hastily erected in his honour. Then in rides the impostor who has caused him to be branded an outlaw - and Valko manages to salvage his reputation and mete out deadly justice.