Butch Cavendish was the right-hand man of Latham Cole and he was responsible for the death of John's brother Dan Reid. He and his men kill all the Texas Rangers, and Butch personally killed Dan. He cuts Dan open and devours his heart. When John saw this, he vowed to take Butch to justice. Butch and Latham were also responsible for the extermination of Tonto's people.
Early in the film he is being transported by train back to town, supposedly so he can be hanged. However using a gun hidden on the train he kills his guards and almost kills Tonto (who is also on the train, purely for the purpose of killing Cavendish). Hearing the commotion, John Reid breaks his way in. But Cavendish holds him at gun point. Tonto however grabs another gun and holds it up against his head, planning to kill him for what he did to Tonto's village. But John stops him, so that he can be tried in a court of law. He then chains him back up, before emptying the gun, declaring there's no place for guns where this train is headed. When asked where that is by Butch, he replies "the Future." At that moment however, Cavendish's gang break in and free him. Cavendish has John chained up and leaves him on the train, which his men had set to crash. Before escaping with his men. Following staging several Commanche attacks, he kidnaps Rebecca and Danny (The Long Rangers brother's wife and son). It is here at his camp he first hears the stories of a mystical "ranger" who killed two of his men with one bullet from one his men, Frank who encountered John and Tonto.
Although his gang is scared, Butch dismisses the stories of Dan Reid's ghost returning to get him and orders one of his men to shoot Rebecca and Danny. Sympathizing with them the man fakes it and tells them to run. Only for them to be found by Cole. Later at the mine, he forces the workers to work mining all the silver. When told there afraid and there has been a cave in, he simply shoots the man who was complaining and tells them to get back to work. He also savagely beats one of his own men down when he suggests they simply take all the silver they have and leave pointing out there already rich, declaring he "wants it all". However following suspicious goings on, he sends one of his men into the mine. When he doesn't come back he sends two more, they don't come back, but a mine car does. Suspicious he and his men shoot at it before investigating and discovering it to contains lit Dynamite. The explosion killed his men, and disabled him. Captured by the Lone Ranger and Tonto, he mocks the Ranger declaring he's as alive as he is, and no different from him just another "man wearing a mask".
Angrily The Ranger beats him with his gun for what he did to his brother. Tonto tries to kill him, but still wanting him to face justice not vengeance and disillusioned from Tonto's stories, the Ranger takes him away. Leading him through the desert, his hands tied and pulled by the Rangers horse. Eventually the Ranger finds Cole and gives Butch over to him so he can be tried in accordance with the law and have justice. However as Butch was secretly working for Cole, Cole lets him loose later. Where he recaptures Rebecca when she escapes. Then in a several way gun confrontation he recaptures the Ranger. However following a real Commanche attack and Tonto breaking in to save The Ranger they are forced to leave. Wising up to the fact that they're both difficult to kill, Butch throws kerosene and lit dynamite down the passage way after them, deciding that should kill them, before leaving. Unaware they managed to survive the explosion. At Cole's hostile take over of the Railroad cooperation, Cavendish grabs Rebecca and takes her to the board meeting, and helps Cole hold the other share holders at gun point, so they are forced to appoint him the new chairman (Cole having already shot the previous on in the back). However at that point, Tonto steals the train carrying the silver. Cole and Cavendish chase after in another train, while the Ranger on Silvers back chases after them across the top of the train.
By the end of the film, he and The Lone Ranger face off against each other on top of a train, Butch uses Rebecca as a human shield during the fight, before seeing a tunnel dives down holding her, assuming the Ranger would be crushed. However he and Silver manages to jump down in time unknown to him. The Ranger later catches up. Finding he's out of bullets Cavendish threatens to throw Rebecca off the train, The Long Ranger however calls his bluff, Cavendish does but Rebecca lands on Silvers back (just as the Ranger planned). Confronting him, he asks The Ranger what he's going to do, kill him? The Ranger replies "that's right" and tries to shoot him, only to find he is also out of bullets. Butch draws a knife, the Ranger holds up his fists read to fight. Cavendish mocks him asking if "he boxed in Collage" but distracted by Tonto on other train the Ranger punches him out, before replying "for a matter of fact I did".
The two confront again, minutes later in an unattached carriage. Drawing his now loaded gun he points it at the Ranger, Butch mocks him, echoing what he said to him earlier about how his train maybe going to the future, but this "Train is going straight to hell." Only for them both to be knocked about when the car knocks against another, regain his balance the Ranger smiles looking behind Butch and tells him he believes him to be right and adds "enjoy the trip." Before using his whip to grab a tree and escape the carriage. Butch tries to shoot him, quickly he pulls open the doorway only to see what the Ranger saw, the other unattached carriages speeding towards him too fast for him to escape, Butch is later killed when a cart collided with him.
Though Latham Cole was the true main villain of the film, Butch drove the plot of the story and was far more dangerous than Cole.
Butch meeting Tonto and the Lone Ranger after escaping custody on board a train
Butch about to eat the heart of the Lone Ranger's brother, Dan
Butch kidnapping the wife and son of the Lone Ranger's brother
Butch sending his workers into a silver mine
Butch being held at gunpoint by the Lone Ranger
Butch after revealing himself as an accomplice to Latham Cole
Butch confronting the Lone Ranger on another train