St. Marys River (Michigan–Ontario)

St. Marys River
Location of the St. Marys River connecting Lake Superior and Lake Huron in the Great Lakes system
Location
Countries
Province/State
CitiesCanada:
United States:
Physical characteristics
SourceWhitefish Bay (Lake Superior)
  coordinates46°30′02″N 84°36′14″W / 46.50056°N 84.60389°W / 46.50056; -84.60389
  elevation600 ft (180 m)
MouthNorth Channel (Lake Huron)
  coordinates
46°03′20″N 83°54′34″W / 46.05556°N 83.90944°W / 46.05556; -83.90944
  elevation
577 ft (176 m)
Length74.5 mi (119.9 km)
Discharge 
  average2,135 m3/s (75,400 cu ft/s)

The St. Marys River, sometimes written St. Mary's River, drains Lake Superior, starting at the end of Whitefish Bay and flowing 74.5 miles (119.9 km) southeast into Lake Huron, with a fall of 23 feet (7.0 m). For its entire length it is an international border, separating Michigan in the United States from Ontario, Canada.

The twin cities of Sault Ste. Marie, Ontario, and Sault Ste. Marie, Michigan, are connected across the St. Marys River by the Sault Ste. Marie International Bridge. The St. Marys Rapids are just below the river's exit from Lake Superior and can be bypassed by huge freight ships through the man-made Soo Locks and the Sault Ste. Marie Canal.

Two of the Ontario tributaries of this river are the Garden River and the Bar River. Other Canadian tributaries include Fort Creek, the Root River, the Little Carp River, the Big Carp River, the Lower Echo River, Desbarats River, and the Two Tree River. The US tributaries to the St. Marys River are the Gogomain River, the Munuscong River, the Little Munuscong River, the Charlotte River, and the Waiska River.