St. Clair County, Michigan

St. Clair County
County
Fort Gratiot Light
Seal
Location within the U.S. state of Michigan
Michigan's location within the U.S.
Coordinates: 42°56′N 82°40′W / 42.93°N 82.67°W / 42.93; -82.67
Country	United States
State	Michigan
Founded	March 28, 1820 (created) 1821 (organized)[1][2]
Named for	St. Clare of Assisi
Seat	Port Huron
Largest city	Port Huron
Area
• Total	837 sq mi (2,170 km2)
• Land	721 sq mi (1,870 km2)
• Water	115 sq mi (300 km2)  14%
Population  (2020)
• Total	160,383
• Density	190/sq mi (70/km2)
Time zone	UTC−5 (Eastern)
• Summer (DST)	UTC−4 (EDT)
Area code	810
Congressional district	9th
Website	www.stclaircounty.org

St. Clair County is a county located in the U.S. state of Michigan and bordering the west bank of the St. Clair River. As of the 2020 census, the population was 160,383.^[3] It is the 13th-most populous county in the state. The county seat is Port Huron, located at the north end of the St. Clair River at Lake Huron.^[1][4] The county was created September 10, 1820, and its government was organized in 1821.^[1] It is located northeast of Detroit. It is considered by the State of Michigan to be a part of The Thumb, a peninsula that is surrounded by Lake Huron in the east-central area of the state.^[5] This area is sometimes dubbed the Blue Water Area.^[6]