Valley Of The Lost by Robert E. Howard

Valley of the Lost, a short story by Robert E. Howard, is one of the first weird westerns that combines elements of  fantasy adventure within the setting of the wild west.  John Reynolds is the last surviving member of his family , after a deadly ambush due to a longstanding, West Texas family feud. On the run for his life, Reynolds hides out in what everyone says is a haunted valley. And afterwards , Reynolds may have wished he had tried to shoot it out with his pursuers, instead of learning the weird truth of Lost Valley.