Lake St. Clair

Lake St. Clair
false-color imagery from Sentinel-2, showing Lake St. Clair in April 2023
Lake St. Clair
Location	(Great Lakes)
Coordinates	42°28′N 82°40′W / 42.467°N 82.667°W / 42.467; -82.667
Type	Freshwater lake
Primary inflows	St. Clair River, Thames River, Sydenham River, Clinton River, Pine River
Primary outflows	Detroit River
Basin countries	Canada, United States
Max. length	26 mi (42 km)[1]
Max. width	24 mi (39 km)[1]
Surface area	430 sq mi (1,114 km2)[1][2]
Average depth	11 ft (3.4 m)[1]
Max. depth	27 ft (8.2 m)
Water volume	0.82 cu mi (3.4 km3)[1]
Residence time	7 days
Shore length1	130 mi (210 km) plus 127 mi (204 km) for islands[3]
Surface elevation	574 ft (175 m)
Islands	Gull Island, Harsens Island, Strawberry Island Fantasy Island and Peche Island
Settlements	Detroit
1 Shore length is not a well-defined measure.

Lake St. Clair (French: Lac Sainte-Claire) is a freshwater lake that lies between the Canadian province of Ontario and the U.S. state of Michigan. It was named in 1679 by French Catholic explorers after Saint Clare of Assisi, on whose feast day they first saw the lake.

It is part of the Great Lakes system (although not considered one of the five Great Lakes), and along with the St. Clair River and Detroit River, Lake St. Clair connects Lake Huron (to the north) with Lake Erie (to the south). It has a total surface area of about 430 square miles (1,100 km²) and an average depth of just 11 feet (3.4 m); to ensure an uninterrupted waterway, government agencies in both countries have maintained a 30-foot-deep (9.1 m) shipping channel through the shallow lake for more than a century.