In an interview Lauren Bacall said that she took the role when Robert Mitchum was to be the male lead. When John Wayne took the role after Mitchum was fired she expected to clash with him since she was a left-wing Democrat and he was a right-wing conservative Republican. She said that he was warm and friendly and they did not discuss politics. She later starred with him again in his last movie The Shootist (1976).
Lauren Bacall on "Blood Alley": "That was supposed to be Mitchum, but he got into some brouhaha - probably had a few too many. William Wellman was great; Wild Bill, a fascinating man! Not a good movie, but I liked working with Duke. We didn't agree politically, but we got along well and had a sort of chemistry."
Robert Mitchum was originally cast as Captain Wilder. He was fired from the film after an altercation in which he shoved the film's transportation manager into San Francisco Bay. Director William A. Wellman complained to Wayne that the star "was on dope, always walking about six inches off the ground." Wellman said either he or Mitchum had to go. Gregory Peck subsequently turned down the role, and Humphrey Bogart wanted a $500,000 salary, which would have put the film over budget. Without a major male star involved, Warner Bros. contacted producer John Wayne, threatening to pull out of their distribution deal for the film unless he took the role himself. To keep his new production company Batjac afloat, Wayne agreed to play Captain Wilder.
John Wayne appeared in an episode of I Love Lucy (1951) to promote this film. In a scene when Lucy is hiding in Wayne's trailer on set, a worker brings in the large poster for "Blood Alley" for his approval just before he is about to receive a massage. As Lucy tries to sneak away, he hears her and makes her give the massage without ever seeing her.
In the scene where they are taking on wood in the ship graveyard, this was filmed at the San Pablo Yacht Club/Marina. The hulls of ships there were placed there to provide a breakwater into the marina.
Average Shot Length = ~6.2 seconds. Median Shot Length = ~5.6 seconds. Both of these figures are fast for an early CinemaScope film, and much faster than William A. Wellman's first CinemaScope film, The High and the Mighty (1954).
On 6 September 2016 the 87 foot stern-wheeler Spirit Of Sacramento mysteriously capsized and sunk in the San Joaquin Delta near Bethel Island. News reports were that it was used in Blood Alley. Previously it was used for tours and charters. It was at anchor at the time and the two people that were on board at the time were reportedly uninjured.