Trigger, formerly Golden Cloud, was the horse that Olivia de Havilland rode in The Adventures of Robin Hood (1938). Rogers eventually bought Trigger for $2,500.
This was originally scheduled as a Gene Autry vehicle (under the title "Washington Cowboy") but Roy Rogers replaced Autry after a salary dispute between Autry and Republic Pictures.
This was Roy Rogers' first starring film for Republic Pictures, and while he was a hit with movie fans and exhibitors, it was a full five years (1943) before he received billing as "King of the Cowboys".
The one song that Gene Autry co-wrote for this film was "Listen to the Rhythm of the Range" and it WAS credited to him. The song "Dust" was written solely (music and lyrics) by Johnny Marvin, and was never part of any dispute between Autry and Republic. That dispute was over salary and personal appearances by Autry, and it was settled out of court when the studio presented Autry with a new contract.
The newspaper headline that opens the movie reads "Dust and Drouth Sweep Southwest".