 Fort McKenzie prospector Pop Kellogg (Sam Flint), just before the arrival of his newly-orphaned grandson Billy (Pat Mitchell), is killed by McBeau (John Crawford) and Dawson (Duke York), who seek the map showing Pop s secret oil claim. Billy, the now newly-doubled-orphaned grandson, is being escorted to Fort McKenzie by Corporal Rod Webb (Kirby Grant) of the Canadian Mounties and his Wonder Dog, Chinook. Webb turns Billy over to the keeping of Ann DuMere (Gloria Saunders), who runs the trading post for Dan Morgan (Warren Douglas). After several attempts on his life, Rod and Ann manage to link Morgan and a mineralogist, Kincaid (Tristram Coffin), to the LeBeau/Dawson gang, which is now minus LeBeau who has been knocked over a cliff to his death by Chinook.