In the 10th film of the Hopalong Cassidy series, Russell Hayden makes his first appearance as Cassidy's sidekick/protégé "Lucky" Jenkins. The trio of William Boyd, Russell Hayden, and George Hayes (known as "Gabby" Hayes) forms the most popular pairing in the series. The movie follows Hopalong Cassidy and his friends as they buy a ranch in Wyoming, only to discover that cattle rustlers are causing trouble in the area. They suspect Andrews, the deputy government agent, of being the leader of the rustlers. When Lone Eagle, a half-breed, is found murdered, Andrews incites the Indians to attack the white men. Cassidy gains the trust of the Indian chief by pointing out that Lone Eagle was half-bad because he was half-white, and they join forces to defeat the rustlers in a mounted charge.
Hills of Old Wyoming
Clashing cultures and unity are put to the test as a ruthless deputy manipulates Native American half-breeds to steal cattle, sparking hostility between ranchers and indigenous groups.