Summoned to Shadow Ranch by his friend Ranny Williams, Sim Baldwin arrives to find Ranny has been ambushed and murdered. Sim learns ranch owner Ruth Cameron is under pressure to sell out to Dan Blake, as the dam on the ranch controls the town's water supply. Vowing to avenge his old friend's death, Sim takes up Ruth's fight and incurs Blake's hostility.

Lumberjack Anthony Briggs has lived alone in the Canadian North Woods ever since his wife took their daughter and ran off to New York City with Robert Lacey, the lumber camp foreman. One day he comes across young Indian chief Lone Wolf and his sister Na-ta-Le, whose tribe has been wiped out by a "spotted sickness", and adopts them. Years afterward Briggs' daughter, now a young woman, returns to lead a hunting party with her fiance, Lacey's son Reynard. Complications ensue.