Rose Marie Lemaitre (Ann Blyth), an orphan living in the Canadian wilderness, falls in love with her guardian, Mike Malone (Howard Keel), an officer of the Royal Canadian Mounted Police. The feeling is mutual. But, when she leaves to learn proper etiquette, Rose Marie meets a trapper named James Duval (Fernando Lamas), who also falls for her. Further complications arise when Native American Chief Black Eagle — a rival of Duval’s — is murdered.