The reclusive novelist B. Traven was asked if he would like to visit the set during location shooting. He demurred, but said he would be sending an associate instead. The associate was actually Traven himself, using a pseudonym.
John Huston was fascinated by mysterious author B. Traven, who was a recluse living in Mexico. Traven approved of the director and his screenplay (by letter, obviously), and sent his intimate friend Hal Croves to the location to be a technical advisor and translator for $150 a week. The general consensus is that Croves was in fact Traven, though he always denied this. Huston was happy not to query him on the subject but his then-wife Evelyn Keyes was certain Croves was the mysterious author, believing that he was continually giving himself away, saying "I" when it should have been "he", and using phrases that were exactly the same as those to be found in Traven's letters to Huston. All very ironic, especially considering that Traven was offered $1000 a week to act as technical advisor on the film. It is known that "B. Traven" was a pen name, and Traven's true identity remains a mystery to this day.
A doctor was assigned to the unit in Mexico and one night he had to attend to John Huston, who had an adverse reaction to marijuana, having smoked it for the first time with his father. He never touched the stuff again.
John Huston played one of his infamous practical jokes on Bruce Bennett in the campfire scene in which he eats a plate of stew. Bennett knew that his character was starving so he wolfed down the food as quickly as possible. Huston then demanded another take. And another. In both extra takes the rapidly filling-up Bennett again had to eat a large plate of stew. Unbeknownst to him, Huston had been happy with the first take. The cameras weren't even rolling for the second and the third. He just wanted to see how much food Bennett could lower before he became too stuffed. As soon as the joke was revealed, Huston added insult to injury by calling for a lunch break.
There were scenes in which Walter Huston had to speak fluent Spanish, a language he did not know off camera. To fill this need, John Huston hired a Mexican to record the lines, and then the elder Huston memorized them so well that many assumed he knew the language like a native.
Walter Huston learned his famous jig from playwright Eugene O'Neill when he was performing in O'Neill's play "Desire Under the Elms" in 1925. This most famous of dances was unscripted and was Walter's idea.
Humphrey Bogart started losing his hair in 1947, round about the time he was making Dark Passage (1947), partly because of hormone shots he was taking to improve his chances of having a child with wife Lauren Bacall (although his excessive drinking and lack of vitamin B were probably also factors in his hair loss). He was completely bald by the time he arrived in Mexico. Once on location, Bogart started taking vitamin B shots, and some of his hair grew back. But he did sport a wig throughout the entire shoot, albeit one that was artfully muddied and matted to cover up the joins.
When John Huston first started working on the project in 1941, the studio had George Raft, Edward G. Robinson and John Garfield in mind for the three main roles. Then World War II intervened. By the time Huston came back from making several documentaries for the war effort, Humphrey Bogart had become Warner Brothers' biggest star. This was entirely appropriate, for when Bogart first got wind of the fact that Huston might be making a film of the B. Traven novel, he immediately started badgering Huston for a part.
As production dragged on, Humphrey Bogart, who was an avid yachtsman, was starting to get increasingly anxious about missing the Honolulu Classic, the Catalina-to-Hawaii race in which he usually took part. Despite assurances from the studio that he would be wrapped on the picture by then, he started to constantly dog John Huston about whether he would be done in time. Eventually Huston had enough and grabbed Bogart by the nose and twisted hard. Bogart never asked him how long before the shooting was over again.
Just as John Huston was starting to shoot scenes in Tampico, Mexico, the production was shut down inexplicably by the local government. It turns out that a local newspaper printed a false story that accused the filmmakers of making a production that was unflattering to Mexico. Fortunately, two of Huston's associates, Diego Rivera and Miguel Covarrubias, went to bat for the director with the President of Mexico. The libelous accusations were dropped.
Director John Huston had read the book "The Treasure of the Sierra Madre" by B. Traven in 1936 and had always thought the material would make a great movie. Based on a 19th-century ballad by a German poet, Traven's book reminded Huston of his own adventures in the Mexican cavalry. When Huston became a director at Warner Bros., the smashing success of his initial effort, The Maltese Falcon (1941), gave him the clout to ask to write and direct the project, for which Warner Bros. had previously secured the movie rights.
In his Oscar acceptance speech, Walter Huston said, "Many, many years ago, I brought up a boy and I said to him, 'Son, if you ever become a writer, try to write a good part for your old man sometime'. Well, by cracky, that's what he did!"
Initially thrilled at Walter Huston's scene-stealing performance, as the shoot wore on producer Henry Blanke started to have second thoughts about Huston upstaging the film's star, Humphrey Bogart, and so John Huston started to get notes from the studio telling him to tone down his father's performance.
John Huston at the time had not been married very long to Evelyn Keyes, who he constantly belittled and humiliated on the location shoot. Eventually Keyes returned to Hollywood to shoot another picture. During this time Huston decided that he wanted to adopt a little orphan boy called Pablo who had been hanging around the set. Keyes first got wind of this when she greeted Huston and Pablo at the airport upon their return from Mexico.
The favorite movie of Perry Smith, one of the killers executed for the infamous Clutter family murders in Kansas as chronicled in Truman Capote's famous book "In Cold Blood". Robert Blake, who appears in this film under his real name of Mickey Gubitosi, would go on to play Smith in the film version of the book, In Cold Blood (1967).
Ann Sheridan is listed as a cast member in a modern source for the role of "Streetwalker," but she did not appear in the film. A streetwalker did appear near the start of the film, but it was not Sheridan.
Filmed in Mexico, though Warners' studio head Jack L. Warner had the unit return to Hollywood when the budget started to exceed $3 million (Warner, however, did admit that he thought the film was one of the greatest ever made).
When offered the part of the old-timer, Walter Huston was not keen to accept. He still saw himself as a leading man and the opportunity to play a secondary supporting part--without his own false teeth--did not appeal to him. Fortunately, he had a change of heart and won a Supporting Actor Oscar for his pains.
Paul Kohner was the agent for both John Huston and Walter Huston. He also represented B. Traven, the author of the original novel, but had never met the notoriously reclusive writer. A diminutive little man did show up at the Mexican location, claiming to be Traven's representative; John Huston and Kohner were firmly of the opinion that this was actually Traven himself.
The trivia items below may give away important plot points.
John Huston's original filmed depiction of Dobbs' death was more graphic - as it was in the book - than the one that eventually made it onto the screen. When Gold Hat strikes Dobbs with his machete, Dobbs is decapitated. Huston shot Dobbs' (fake) head rolling into the waterhole (there's a quick shot of Gold Hat's accomplices reacting to Dobbs' rolling head that remains in the film and in the very next shot you can see the water rippling where it rolled in). The 1948 censors would not have allowed that, so Huston camouflaged the cut shot with a repeat shot of Gold Hat striking Dobbs. Warner Bros' publicity department released a statement that Humphrey Bogart was "disappointed the scene couldn't be shown in all its graphic glory". Bogart's reaction: "What's wrong with showing a guy getting his head cut off?"
With a budget exceeding $3.5 million, this was the most expensive production ever mounted by Warner Brothers up until 1948, with the added uneasiness of it being shot in Mexico. To protect their investment the studio bosses insisted Bogart's character, Fred C. Dobbs remain alive until the very end of the script (after initially not wanting Dobbs to die at all). John Huston steadfastly resisted studio interference. While critically acclaimed, the film was a financial disappointment during its initial release.