There had been plans for another film featuring the character Rooster Cogburn, to be entitled "Someday", but it was canceled when this movie proved to be only a moderate hit at the box office. In addition Paramount Pictures felt that John Wayne had become too old to carry a successful movie, and that in any case audiences in the mid-1970s were not interested in westerns.
During filming John Wayne was injured teaching his eight-year-old daughter to play golf, but fortunately his eye patch concealed the mark. He had been working on one lung for the past ten years and had great difficulty breathing due to the high altitude, often needing to breathe through an oxygen mask.
Richard Jordan later admitted he decided to overplay his part because he thought the movie was going to flop, and if anybody paid to see it then it would only be for the two stars. He also said he felt that Katharine Hepburn was about to die at any minute - ironically, she outlived him by a decade.
During location filming, the crew wore printed t-shirts that read "We love Brother John" on the front and "...and Sister Kate, too!" on the back. John Wayne and Katharine Hepburn were, reportedly, very much amused by this.
Richard Fleischer was originally offered the director's job by the studio and accepted it. John Wayne, however, had director approval and was still irked at Fleischer for having turned down North to Alaska (1960) 15 years previously, and vetoed Fleischer as director. It was eventually given to Stuart Millar.
Director Stuart Millar insisted on so many takes that eventually John Wayne snapped, "God damn it Stuart, there's only so many times we can say these awful lines before they stop making any sense at all."
Katharine Hepburn was bemused by co-star John Wayne's tendency to argue with everybody, especially the director, during filming. At the party to celebrate the last day of filming she told him, "I'm glad I didn't know you when you had two lungs, you must have been a real bastard. Losing a hip has mellowed me, but you!"
There was some surprise when Katharine Hepburn accepted the role of Eula Goodnight, since more than twenty years earlier she had turned down Geraldine Page's role in Hondo (1953) because she would not work with John Wayne at the height of the blacklist.
Eula mentions a poet, Ella Sturgis Hooper. The real name is Ellen Sturgis Hooper (1812 - 1848). She was member of the Transcendental Club and regarded as one of the most gifted poets among the Transcendentalists of New England.