A range war breaks out between the cattle ranchers and the sheepherders in 19th Century Wyoming. The sons of the faction leaders meet and become friends, leading to tragedy when a hired killer of one faction kills one of the boys by mistake.
Thorpe Henderson is an assassin, a Regulator, hired by the cattlemen to deal with their rustler problem. Thorpe prefers to hide in the brush and kill from 200 yards away but, when bored, isn't afraid to face a man down with pistols at close range. It is 1902 and civilization has made it's way west. The good citizens decide that the time has come to end the lawlessness even if their methods prove to be as amoral as the evil they profess to hate.