The 9 Feb 1962 DV announced that Warner Bros. Pictures secured film rights to the 1962 novel by Earl Hamner, Jr. The movie version would be written, produced, and directed by Delmer Daves. The 22 Feb 1962 DV noted that actors Glenn Ford and Connie Stevens were being considered for roles. By 2 Jun 1962, veteran actor Henry Fonda was cast as "Clay Spencer," as stated in that day's NYT. A news item in the 20 Jun 1962 DV indicated that Carol Lynley was to be loaned out by her home studio, Twentieth Century-Fox. One week later, the 27 Jun 1962 issue reported that cast and crew were leaving that day for Jackson Hole, WY. Location filming was expected to last five weeks, according to the 28 Jun 1962 LAT. Principal photography began 29 Jun 1962, as stated in 6 Jul 1962 DV production charts.
       The 13 Jul 1962 LAT noted that character actress Beulah Bondi joined the cast as "Miss Parker," but she was replaced the following month by Virginia Gregg, as stated in the 24 Aug 1962 edition.
       Other casting announcements included Martin Eric, Fred Marlow, and Guy Wilkerson (5 Jul 1962 DV); Tom Harker, Karma Jean Brown, Myrna Richardson, Karen Hathaway, Roberta Richardson, Linda Lunz, Gretchen Stainbrook, Ruth Ann Williams, Maryanna Zabawa, Linda Vandenburgh, Linda Sue Robinson, Linda C. Pulliam, and Marilynn M. Riggan (23 Jul 1962 DV); Judy Nicholas, Patricia Sue Taylor, Julie Gardner, Johanna Means, Jeanette L. Terrill, Becky Morton, Peggy Potter, Maydene Baxter, Louis M. Turner, and Hobard DeWolfe (24 Jul 1962 DV); Rory Mallinson and Rusty Lane (13 Aug 1962 DV).
       Following the completion of principal photography, the 29 Aug 1962 Var revealed that Delmer Daves composed his screenplay by typing on the right-hand page, leaving the opposing page blank for sketching "scenes, backgrounds, characters and action" in square panels, similar to a comic book. Although Daves scheduled a longer shoot, he was able to end production a week ahead of schedule, saving the studio approximately $100,000. Daves planned to spend three days per week on post-production at the Warner Bros. Burbank, CA, studio, while devoting the remaining days to developing the screenplay for his next picture, Youngblood Hawke (1964, see entry).
       The 16 Aug 1962 DV announced that the expletives used in the film, such as "hell" and "damnation," were permitted by the Association of Motion Pictures Producers' Code, "because this type of language is not offensive." Daves described the expletives as "folksy descriptions, dealing with extravagant images."
       Composer Max Steiner began recording his score on 30 Nov 1962, using a fifty-piece orchestra, as noted in that day's DV. Two months later, the 30 Jan 1963 Var reported that the film was scheduled to open the following May at Radio City Music Hall in New York City. On 19 Feb 1963, DV stated that Warner Bros. began a series of exhibitor screenings that day, in thirty-two major cities. The studio also planned to have their field agents work with newspaper editors and others in the media to cross promote the film with the Studebaker Corporation's new Wagonaire station wagon.
       Celebrity Arthur Godfrey heartily endorsed the film in the 27 Feb 1963 Var, and later told the 26 Apr 1963 LAT he intended to fly Henry Fonda and several other cast members in his private airplane to a press screening in Jackson Hole, scheduled for 27 May 1963, according to the 15 May 1963 Var. An item in the 29 May 1963 issue estimated the audience at 250. The event continued through the next several days with the dedication of "Spencer's Mountain," a peak in Grand Teton National Park. In attendance were WY Senator Gale McGee, Governor Clifford Hansen, Delmer Daves, and cast members Henry Fonda, Maureen O'Hara, James MacArthur, and Mimsy Farmer.
       Spencer's Mountain opened 16 May 1963 at Radio City Music Hall, followed by 24 Jul 1963 openings in Los Angeles, CA. Although reviews were generally positive, the 17 May 1963 NYT complained that the film was "so prettied-up with Hollywood make-believe and sentimentality" that it failed to capture its intended "naturalness and emotional quality." Articles in the 5 Jun 1963 NYT and the 12 Jun 1963 Var stated that Warner Bros. would reduce its advertising space in the New York Herald Tribune after critic Judith Crist gave the film a negative review. A spokesman for the studio insisted that the decision was prompted by Crist's follow-up article, in which she disparaged Radio City Music Hall "for not providing family entertainment." Warner claimed it was showing solidarity with the theater, adding that Crist's readership was typically not interested in the studio's product. The public approved the picture, earning it more than $4 million in rental fees, according to the 8 Jan 1964 Var.
       The 23 Apr 1963 DV reported that Warner Bros. planned to release a short subject, Vacationlands, U.S.A., to theaters free of charge. The film included sequences from Spencer's Mountain, along with additional footage of Grand Teton National Park.
       Earl Hamner, Jr., later adapted his characters from the novel, Spencer's Mountain, for the television series, The Waltons (CBS, 14 Sep 1972 - 4 Jun 1981), and two television movies, The Homecoming: A Christmas Story (1971), and A Wedding on Walton's Mountain (1982).