SOO meaning in Regional ?

Sault Ste. Marie ( SOO-seint-ma-REE) is the only city and county seat of Chippewa County in the U.S. state of Michigan. With a population of 14,144 at the 2010 census, it is the second-most populated city in the Upper Peninsula after Marquette. It is the central city of the Sault Ste. Marie, MI Micropolitan Statistical Area, which encompasses all of Chippewa County and had a population of 38,520 at the 2010 census.

Sault Ste. Marie was settled as early as 1668, which makes it Michigan's oldest city and among the oldest cities in the United States. Located at the northeastern edge of the Upper Peninsula, it is separated by the St. Marys River from the much-larger city of Sault Ste. Marie, Ontario. The two are connected by the Sault Ste. Marie International Bridge, which represents the northern terminus of Interstate 75. This portion of the river also contains the Soo Locks, as well as a swinging railroad bridge. The city is also home to Lake Superior State University.