Mack MacLane of the Royal Mounties, and Kenneth MacDonald as Mort Ramsome, the head villain.

The trading post of Sitkawan, Canada is taken by surprise when an Indian tribe attacks and massacres the settlers aboard a fur-bearing wagon train.

MacLane soon realises that the attackers were led by Mort Ransome, a nasty renegade, who had been conspiring with Black Bear, medicine man of the tribe, to incite the heretofore friendly Indians for his own gain.

He also learns that two white renegades have kidnapped Diana Blake, daughter of the local post factor, and saves her from a runaway wagon just before it plunges over a cliff.

Perils of the Royal Mounted also features stereotypically Northern genre elements including fur trappers, lumberjacks, trading posts, rebellious Indian braves, forest fires, avalanches, and a wide range of dangerous wildlife.