Railroad Detective Matt Clark and his assistant Frankie Adams investigate the stealing of a herd of horses belonging to the U. S. Cavalry. They learn that the leader of the outlaws is a woman named Belle Starr.
Matt and Frankie set out on the trail of cattle rustlers led by one of the West's youngest and most notorious outlaws.
Railroad detectives Matt Clark and Frankie Adams pursue the vengeful James brothers, Frank and Jesse, who declare war on the law after their young half-brother is killed in a police ambush.
Railroad detectives Matt Clark and Frankie Adams go after Apache chief Geronimo, who has been identified by Joe Burns, the night watchman of the railroad yards, as the leader of a band of freight-car robbers.
Matt and Frankie head to Sweetwater, Wyoming where major cattle ranches are suffering heavy losses. A woman nicknamed Cattle Kate becomes the focus due the number of livestock she sells despite her small operation.