No, I've never been to the province. But a quick look at a relief map will show that all but the very southwest corner of Saskatchewan is prairie. Nevertheless mountains loom in the background in every shot of this film which is supposed to take place in the central part of the then-territory. The film is not alone in this; there are no mountains in western Oklahoma either, contrary to "True Grit." Alan Ladd plays O'Rourke, a RCMP officer with a progressive bent who must battle his mutton-headed commander as well as the Indians. Shelley Winters, here in her brief Marilyn Monroe-competitor period, is an American fugitive in a low cut dress. Unless you don't see many movies, you can probably surmise complications arising between the two. Jay Silverheels, later of "Lone Ranger" fame, is O'Rourke's Cree companion who angrily leaves him when the RCMP insist on confiscating the tribe's rifles and who must later confront his former friend.
A previous post noted that the RCMPs are wearing "Smokey Bear", not the correct "sepoy" hats. More noticeable to me was the dress of the Indians, who always look to be gussied up for a powwow. Photographs of the time show that by the late 1800's Indians usually dressed in manufactured (i.e. white) clothes with a some Native touches. Common sense also makes me doubt leaders wore the heavy, conspicuous headresses into battle, although again this film is not alone in this.
The plot involves the entry of the Sioux into Canada in the aftermath of Little Big Horn. In reality, the fragmented Sioux could hardly attempt a takeover of Western Canada, but merely hoped to find refuge from the vengeful U.S. Army. But here the setup is for a spectacular mass battle at the end, showing Indians charging en masse into white firepower the way they almost never did in actual history. Noticeably missing from depiction, by the way, are the Sioux women and children who trekked into Canada along with the warriors.
Because of the spectacular backdrops in Technicolor, this is not too terrible an oater if only to see the conventions of the period.