Clark Gable was anxious to do the film because his father had been an oil rigger, and Gable himself had worked on oil rigs in Oklahoma before becoming an actor.
This was the last of three films (after San Francisco (1936) and Test Pilot (1938)) that Clark Gable and Spencer Tracy made together. After this film, Tracy insisted on a clause in his MGM contract that he would receive equal billing with Gable in all future films. While the two remained lifelong friends, they were never again paired together because MGM wasn't sure how to handle the equal billing. Tracy deliberately associated less with Gable after 1942 as he was trying to stay off alcohol, and Gable was always constantly surrounded by alcohol.
Although M-G-M paid a high price for the services of Oscar® winner Claudette Colbert, the studio's contracts with both Clark Gable and Spencer Tracy obligated them to bill both male stars above Colbert, who usually insisted upon top billing on any project. She accepted being billed third for the opportunity of working with Gable a second time after their first project together, It Happened One Night (1934), won both of them Academy® Awards.
Hedy Lamarr wears the same style of hat that Greta Garbo made famous a year earlier in Ninotchka (1939).
The only re-teaming of Clark Gable and Claudette Colbert after their Oscar® winning performances in It Happened One Night (1934).