Elvis Presley was inducted into the Los Angeles Indian Tribal Council by Native American Wah-Nee-Ota after portraying the son of an Indian and a white settler in this film.
Barbara Steele walked off the picture after an argument with director Don Siegel. She was replaced by Barbara Eden.
Andy Warhol's famous diptych of Elvis Presley as a cowboy came from a shot in this movie.
Elvis Presley had another song in the film, "Summer Kisses, Winter Tears", which was cut after preview audiences laughed at the staging (Elvis singing to the Indians around a campfire, accompanied by a chief on war drums). A studio version of the tune was recorded, but the original "Indian" version was only resurrected recently on the German "Elvis: Double Features" CD collection.
The original title for this movie was "Black Star". Elvis Presley even recorded a song by that name. After the title was changed he re-recorded the song, using the same words and melody but changing the word "black" to "flaming". The song "Black Star" was unreleased for years, until it appeared on the Elvis boxed set "Collectors Gold" in 1991.
A song called "Britches" was recorded for the movie, It was intended that Elvis Presley would sing it while riding his horse to the crossing together with his brother Clint. Elvis, however, didn't want to perform a song while riding because it would look too dumb.
In the beginning of the movie, Angus Pierce (Richard Jaeckel) has no partner with which to dance, so he grabs a wooden chair. "The warden said, "Hey, buddy, don't you be no square. If you can't find a partner use a wooden chair." This line is from the title song of the Elvis Presley film, Jailhouse Rock (1957).
In June 1960 The Hollywood Reporter wrote that the studio had opened negotiations with Michael Curtiz to direct the film after Nunnally Johnson was no longer the director. Curtiz had directed Elvis Presley in King Creole (1958) and was originally set to direct him again in G.I. Blues (1960).
The original paperback version of this novel by Clair Huffaker was entitled "Flaming Lance".
Robert Wagner says in his memoirs he was offered the role of Elvis' brother but turned it down " ... because nobody ever paid attention to any other man in an Elvis Presley picture - Colonel Tom Parker made sure of that". Steve Forrest was cast in his place.
An August 1960 The Hollywood Reporter news item noted that Diane Baker was originally to co-star with Elvis Presley.
Buddy Adler was set to executive produce the film, but he died on July 12, 1960, prior to the start of principal photography. The extent of his contribution to the production prior to that time has not been determined.
In May 1958 The Hollywood Reporter wrote that Nunnally Johnson had been slated to write, direct and produce the film. During the same month, Daily Variety wrote that Johnson wanted Marlon Brando and Frank Sinatra to play the brothers. Eventually Johnson only worked as a writer on the film.