Mounties, Cree and the Sioux. Saskatchewan is directed by Raoul Walsh and written by Gil Doud. It stars Alan Ladd, Shelley Winters, J. Carrol Naish, Hugh O'Brian, Jay Silverheels, George Lewis and Robert Douglas. Music is by Joseph Gershenson and cinematography in Technicolor is by John F. Seitz. Saskatchewan River Country, Spring 1877, and Mountie Sergeant O'Rourke (Ladd), who was reared by the Cree Indians, sets about trying to prevent the Cree from joining forces with the Sioux who have crossed the border into Canada after massacring General Custer at Little Bighorn. Competent story with…