Based loosely on the true story of Cattle Kate and her husband (who were hanged as cattle rustlers from a cottonwood tree near the Sweetwater River in the late 1800's), The Last Gunfighter tells the story of haunted U.S. deputy marshal John Bronson.

A bloody and deadly gunfight in Laramie, Wyoming pushed John into solitary retirement from his law enforcement career. Now panning for gold in the mountains of Wyoming , an ominous letter from his sister brings him back to active duty, for she tells him that the Stock Grower's Association is finding reasons to hang homesteaders and drive them off their land.

His sister and her husband have already been wrongfully lynched by the time he arrives, but he learns that their son has been taken captive. Now it's up to him — and his gun — to rescue his nephew and end the murderous rampage once and for all.