Debbie Reynolds was filming this simultaneously with How the West Was Won. Actor Barry Livingston's brother was working on that film. Barry remembers fondly that Debbie was playing his foster mom during the week, and his brother's grandmother on the weekends.
The last complete feature film shot in the VistaVision wide screen process. (VistaVision is still used for some special effects work, but not complete films.)
It was during the filming of this movie that Cliff Robertson learned that President Kennedy had personally chosen Cliff Robertson to play him in PT 109 (1963).
The first feature film where actor Casey Adams changed his name to Max Showalter.