Bronco, working as a sheriff, welcomes his pretty young cousin Amanda, who has come from Atlanta hoping to find more excitement in life. Unfortunately one of the things she finds exciting is a young gunfighter who has his own devious plans for the town's upcoming social event.
Bronco hires on as a guide to three men and a woman who claim to be starting a business in another town. Actually they are a gang of robbers who have already killed one Pinkerton agent, and are now being pursued by another.
Bronco is assigned to keep the peace between feuding outlaws Butch Cassidy and Billy Doolin as they - and their gangs - visit the town of Painted Rock for the wedding of Cassidy's niece and Doolin's brother. However, a local saloon owner plans to take advantage of the situation to rob the bank and let the outlaws be blamed for it.
Bronco and hard-drinking Irishman Terrence Harrigan are fired after the stage they were guarding is attacked, its passengers killed and the gold shipment it was carrying stolen. Both Harrigan and Bronco decide to fight the gang responsible by infiltrating it.
Bronco finds himself involved in a feud ranchers Matt Wigram and Jim Gant, and with the friction between Gant and his son, who is anxious to get out on his own and prove himself independent of his father. Wigram decides to take advantage of this in order to get Gant's land, even by killing the son.
A Northern doctor jailed for treason for treating Confederate soldiers during the war returns to his home town after his release. Four men whom he threatened at his trial fear he plans revenge, but Bronco believes the doctor when he says he's forgiven everyone. But the man still tells one of the four men they are all going to die, and soon one of them does.
Bronco wins 1000 head of cattle in a poker game. However, when he tries to bring them to market, he runs into one rancher who charges him outrageous fees for grazing rights and another who won't let Bronco cross his property to take the cattle to market.
Bronco comes across a stagecoach that went over a cliff and finds only one surviving passenger - a young woman who switched clothes with one of the dead nuns she was riding with. He takes her to the nearby mission, where she meets the man they both were looking for, Mike Bestor, a wanted desperado's former associate, now helping the mission's sisters and children. The phony nun is only interested in the money he has hidden, but Bestor is grateful to the mission's nuns and wants to give it back. Also, the gang leader Bestor broke with wants to get the money and get his...
Bronco is working undercover with the Army to seek out the identity of a former Confederate guerrilla who is still at large and find out what has happened to a large cache of stolen Union gold. He becomes involved with a beautiful woman card dealer who could be an escaped Confederate spy. Bronco wins her trust and uses it to infiltrate their ring and get close to the truth.
Just after the end of the Civil War and President Lincoln's assassination, Bronco is consigned to lead a group of ex-Confederates in delivering a shipment of a million dollars in gold to Benito Juarez, at Lincoln's request, to be used to overthrow the French puppet emperor Maximilian. On the way, Bronco has to deal with hostile Comanches as well as untrustworthy members of his group and a female stowaway running from the law.
Bronco is leading a cattle drive to Abilene, Kansas, a town still torn apart by hostility over the Civil War. One of his drovers, a young ex-Confederate, gets into continuous trouble over his past, and a woman hopes to use him to get revenge on Abilene Marshal Wild Bill Hickok.
Bronco is traveling across the Rio Grande River, which separates the US from Mexico, when he sees a woman and a young boy who are crossing from the Mexican side being shot at. He helps them across and finds shelter at the cabin of an old widow. He is then astonished to learn that the boy is the son of the late Emperor of Mexico.
A stubborn old farmer refuses to move from land which has been cleared for the building of a dam, and neither Bronco, the Army, or even the Governor can persuade him to. A newspaperman's story makes the man into a hero and turns sentiment against those trying to evict him, but someone else is trying to force the old man and his granddaughter out through more unscrupulous means.
Bronco leads a wagon train of ex-Confederates from Virginia on their way to Oregon. Complicating matters are a Yankee charged with robbery and murder who is stowing away in one of the wagons, and an outlaw group led by a man who wants revenge on Bronco, whom he blames for his court-martial.