Overland Mail is a 1942 American Western film serial from Universal Pictures which stars Lon Chaney Jr., Noah Beery Jr. and Noah Beery Sr.
It was subsequently edited into a film version called The Indian Raiders in 1956.
Two investigators for a stagecoach company are assigned to discover why the company's stages keep being ambushed.
They find that the culprits are bandits disguised as Indians, and they set out to find out who is behind the plot.
You can help Wikipedia by expanding it.This article related to an American film of the 1940s is a stub.