Sault Ste. Marie is a city in, and the county seat of, Chippewa County in the U.S. state of Michigan. It is situated on the northeastern end of Michigan's Upper Peninsula, on the Canada–US border, and separated from its twin city of Sault Ste. Marie, Ontario, by the St. Marys River. The city is relatively isolated from other communities in Michigan and is 346 miles from Detroit. The population was 14,144 at the 2010 census, making it the second most populous city in the Upper Peninsula.