Soo

Soo is a common shorthand for Sault Ste. Marie, a pair of neighboring cities on opposite sides of the Canada–United States border. The Canadian city is in Ontario, and the American city is in Michigan; both sit at the mouth of the St. Marys River where it connects Lake Superior to Lake Huron. Locals often refer to the area collectively as “the Soo.”

The name Sault Ste. Marie derives from the French sault, meaning rapids, with Sainte Marie attached to the patron saint. The shortened form “Soo” reflects English pronunciation. The two cities have long Indigenous histories and were early sites of European exploration and fur trade, evolving into cross-border communities linked by the river and the Great Lakes.

A defining feature of the region is the Soo Locks on the St. Marys River, which allow ships to bypass rapids and move between Lake Superior and Lake Huron. The lock system is operated by the U.S. Army Corps of Engineers and includes multiple lock chambers; the Poe Lock handles the largest vessels. The locks are central to commercial shipping, supporting trade in iron ore, coal, limestone, and other cargo.

Economy and culture are shaped by tourism, outdoor recreation, and manufacturing. Lake Superior State University operates in Sault Ste. Marie, Michigan, and the Sault Ste. Marie Greyhounds compete in the Ontario Hockey League on the Ontario side. The historic Soo Line Railroad, the Minneapolis, St. Paul and Sault Ste. Marie Railway, linked the region to broader markets and remains part of its industrial heritage. The two cities maintain cross-border institutions and Indigenous communities that contribute to the area's cultural landscape.

Related topics include the Sault Ste. Marie Canal, the St. Marys River, the Soo Locks, and the Soo Line.