According to Ben Mankiewicz on TCM, Barbara Stanwyck did her own stunts during the waterfall scene, and despite becoming black and blue, never held up the production.
According to a contemporary article in the Los Angeles Times, Alan Ladd and Kirk Douglas were being considered for the male lead in this film.
Warner Brothers also released this movie in 2-D.
The locomotive used in this film is the "Sierra No. 3", built in 1891 by the Rogers Locomotive and Machine Works in Paterson, New Jersey. It is probably the most-filmed locomotive in history, being featured in scores of motion pictures and television productions in the 20th Century. It underwent a 3-year overhaul costing $1.6M and returned to service in 2010.