The White Outlaw.

Jack Lupton loves three things in the world, Buck his dog, Scout his horse and the lovely rancher's daughter Mary Gale. But his beloved horse Scout was driven off by man's cruelty and finding freedom, now leads a big herd of horses to run wild! And Jack has his own problems with the cruelty of his fellow man, in the form of James Hill his brutal and jealous rival for Mary's affections!