Lula Parker Betenson, sister of the real Butch Cassidy, often visited the set, and her presence was welcome to the cast and crew. During lulls in shooting she would tell stories about her famous brother's escapades, and was amazed at how accurately the script and Paul Newman portrayed him. Before the film was released, the studio found out about her visits and tried to convince her to endorse the movie in a series of ads to be shown in theatres across the country. She said that she would, but only if she saw the film first and truly stood behind it. The studio refused, saying that allowing her to see the film before its release could harm its reputation. Finally, at Robert Redford's suggestion, she agreed to do the endorsements - for a small "fee."
Katharine Ross enjoyed shooting the silent, bicycle riding sequence best, because it was handled by the film crew's second unit rather than the director. She said, "Any day away from George Roy Hill was a good one." (This was after she had been scolded and banned from the set for operating a camera.)
The more commonly used name for Butch Cassidy and Sundance Kid's gang was The Wild Bunch. However, when the Sam Peckinpah film, The Wild Bunch (1969), was released a few months earlier, the name of the gang was changed to the Hole in the Wall Gang to avoid confusion with Peckinpah's film.
This movie was filmed roughly the same time as Hello, Dolly! (1969), on the sound stage next door. Director George Roy Hill believed that the studio would allow him to film the New York scenes on "Dolly's" sets, since the two films' daily shooting schedules were totally different. After production started, though, the studio informed him that it wanted to keep the sets for "Dolly" a secret and so refused him permission. To work around this, Hill had Robert Redford, Paul Newman and Katharine Ross simply pose on the sets and took photos of them. He then inserted images of the three stars into a series of 300 actual period photos and spliced the two different sets (real and posed) together to form the New York montage.
All the Bolivia scenes were filmed in Mexico, where almost the entire cast and crew, and the director, came down with Montezuma's Revenge (severe diarrhea caused by drinking Mexico's notoriously polluted water). Only Robert Redford, Paul Newman and Katharine Ross were spared, because they refused to drink the water catered on the set and stuck to drinking soda and alcohol for the duration of the shoot.
'Butch Cassidy' (Robert Leroy Parker) was so nick-named because he once worked in a butcher's shop whilst 'The Sundance Kid' (Harry Alonzo Longabaugh) was nick-named this because he once was arrested in the Wyoming town of Sundance.
On the first day of shooting, involving the train robbery scenes, Katharine Ross came to the set to watch. There were five cameras and only four operators, so the DP put her on the extra camera. He showed her how to operate it, and how to move it to get her shot. Director George Roy Hill was furious, but said nothing the whole day. At the end of the day, however, he banned her from the set except when she was working.
The river jump was shot at the studio's Century Ranch near Malibu, CA. Paul Newman's and Robert Redford's stuntmen actually jumped off of a construction crane by Century Lake. The crane was obscured by a matte painting of the cliffs. Newman and Redford start the jump in Colorado, but only land on a mattress.
Paul Newman did his own bicycle stunts, after his stunt man was unable to stay on the bike, except for the scene where Butch crashes backwards into the fence, which was performed by cinematographer Conrad L. Hall.
According to screenwriter William Goldman, his screenplay originally was entitled "The Sundance Kid and Butch Cassidy." Both Steve McQueen and Paul Newman read the script at approximately the same time, and agreed to do it, with McQueen playing the Sundance Kid. When McQueen dropped out, the names reversed in the title, as Newman was a superstar.
In order to get the shot of the "super posse" jumping out of the train on their horses, the door on the opposite side of the train car was left open and a ramp placed out of view on that side of the train. In real life, the horses would not have had room in the train car to make such a dramatic leap.
Before the real Butch Cassidy and Sundance Kid ended in Bolivia, they spent some time in Patagonia (Argentina), in a town called Cholila. After robbing a bank and fleeing that country, they spent a brief time in Chile, where they befriended miner Percy Seibert, inspiration for the character Percy Garris.
Contrary to popular belief, the vocalists on the Burt Bacharach-penned song "South American Getaway" in this film were not The Swingle Singers. It was instead performed by The Ron Hicklin Singers, a group of Los Angeles studio vocalists best known as the real singers behind the background vocals on The Partridge Family recordings.
Ted Cassidy's character Harvey Logan, portrayed as a simple-minded thug, was in fact a suave ladies' man and calculating cold-blooded murderer. He is best known for his clever escape from Knoxville (TN) Jail in 1902. Like Butch Cassidy and the Sundance Kid, his officially reported death (in a 1904 Colorado train robbery) was contested by mutually exclusive eyewitness claims which place him simultaneously on several different continents during the following decades.
With nine wins it currently holds the record for the British Academy Awards (BAFTAs). It won for picture, actor (Robert Redford), actress (Katharine Ross, direction (George Roy Hill, screenplay, cinematography, film editing, sound and score.
The bull's name in the film is "Bill". He was flown in from Los Angeles for the bicycle scene, which was shot in Utah. In order to make Bill charge, the filmmakers sprayed a substance on his testicles. Oddly, he didn't seem to mind and endured it through several takes (from The Making of 'Butch Cassidy and the Sundance Kid' (1970)).
The true identity of the historical person known as "Etta Place" is unknown. Historians have many different theories, a popular one being that she was Fort Worth innkeeper Eunice Gray, who died in a fire in 1962.
Two fictional western characters may have been derived from the name Butch Cassidy (1866-1908): Butch Cavendish, the arch rival of The Lone Ranger, and good guy Hopalong Cassidy, film persona of William Boyd.
Other actors that were under consideration for the role of Sundance were Steve McQueen and Warren Beatty. McQueen withdrew due to billing disagreements, and Beatty declined as he found the film too similar to Bonnie and Clyde (1967).
The trivia items below may give away important plot points.
Though Butch Cassidy and the Sundance Kid were reported killed in San Vicente, Bolivia, on November 7, 1908, the location of their grave has been lost. This has resulted in a long-lived conspiracy theory that their deaths were faked, or that two other men were killed and misidentified as them. Until the 1930s, several eyewitness claims reported encountering one or both men, yet the chronology and geography of the claims are often mutually exclusive. A handwriting expert has claimed that Spokane auto mechanic William T. Philips, who died in 1937, wrote in Cassidy's hand, yet other historians insists that Philips' and Cassidy's known whereabouts on a certain date mark them as separate individuals.
Percy Garris is based on Percy Seibert, a Maryland mining engineer for whom Butch Cassidy and the Sundance Kid worked in Antofagasta, Chile. Contrary to Strother Martin's on-screen death, Seibert was alive when the two died, and served as the coroner's witness. In a 1930 interview, Seibert reaffirmed having identified the two dead in 1908, and insisted that the "William T. Philips" theory was "rubbish". Conspiracy theorists have him lying to the coroner so that his friends could be declared legally dead and start a new life.