The Gambler of the West.

A family is attacked by Indians, the father killed and son captured. The widow remarries and her stepdaughter, Mabel, encourages her stepbrother to find his lost half-brother. Dick, influenced by a gambler, gambles away his money and tries to exploit Mabel, prompting her to join the search with a gambler she meets, Jack. They discover the brother is now an Indian chief, leading to further complications.