Saint Clair River

Saint Clair River
Landsat satellite photo, showing Lake Saint Clair (center), as well as St. Clair River connecting it to Lake Huron (to the North) and Detroit River connecting it to Lake Erie (to the South)
Other name(s)	Rivière Sainte-Claire
Physical characteristics
Main source	Lake Huron
River mouth	Lake St. Clair
Length	40.5 mi (65.2 km)
Discharge	Average rate: 182,000 cu ft/s (5,200 m3/s)
Basin features
Basin size	223,600 sq mi (579,000 km2)

The St. Clair River (French: Rivière Sainte-Claire) is a 40.5-mile-long (65.2 km)river in central North America which drains Lake Huron into Lake St. Clair, forming part of the international boundary between the Canadian province of Ontario and the U.S. state of Michigan. The river is a significant component in the Great Lakes Waterway, with shipping channels permitting cargo vessels to travel between the upper and lower Great Lakes.

The river, which some consider a strait, flows in a southerly direction, connecting the southern end of Lake Huron to the northern end of Lake St. Clair. It branches into several channels near its mouth at Lake St. Clair, creating a broad delta region known as the St. Clair Flats.

The river is 40.5 miles (65.2 km) long and drops 5 feet (2 m) in elevation from Lake Huron to Lake St. Clair. The flow rate averages around 182,000 cubic feet per second (5,200 m³/s), and the drainage area is 223,600 square miles (579,000 km²). This takes into account the combined drainage areas of Lakes Huron, Michigan, and Superior.

In the 18th century, French voyageurs and coureurs des bois travelled on the river to trade with Native Americans and transport furs in canoes to major posts of French and British traders, including Fort Detroit, built downriver in 1701. European demand for American furs, especially beaver, was high until the 1830s.