City (pop., 2000: 16,542), eastern Upper Peninsula, Michigan, U.S. Located on the rapids of the St. Marys River between Lakes Superior and Huron, it is linked to its Canadian twin city, Sault Sainte Marie, Ont. (pop., 2001: 74,566), by road and rail bridges. The U.S. and Canada each operate a part of the Sault Sainte Marie Canals, or Soo Canals, a hub of the Saint Lawrence Seaway. The first U.S. canal went into operation in 1855; it has since been replaced and is now divided into the northern canal (completed 1919) and the southern canal (completed 1896). The Canadian canal, which has one lock, was completed in 1895.