St. Clair County, Michigan facts for kids

Quick facts for kids St. Clair County
U.S. county
Fort Gratiot Light
Seal
Location within the U.S. state of Michigan
Michigan's location within the U.S.
Country	United States
State	Michigan
Founded	March 28, 1820 (created) 1821 (organized)
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

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. 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. The county was created September 10, 1820, and its government was organized in 1821. 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. This area is sometimes dubbed the Blue Water Area.

Etymology

French explorer René-Robert Cavelier, Sieur de La Salle led an expedition to this area on August 12, 1679. They named the lake as Lac Sainte-Claire, because it was the feast day of Saint Clare of Assisi, whom they venerated. English mapmakers adopted the French name, identifying the lake feature as Saint Clare on maps dated as early as 1710. By the Mitchell Map of 1755, the spelling was given as St. Clair, which later became the current version in 1924. Located along the western shores of Lake St. Clair and the St. Clair River, the county was named for them by European-American settlers.

The name is sometimes mistakenly attributed to honoring Arthur St. Clair, an American Revolutionary War general and governor of the Northwest Territory, but it was established long before he was considered a notable figure. The earlier spelling of the lake's name may have been conflated with English practice and the name of the general, as several political jurisdictions near the lake and the river, such as St. Clair County, St. Clair Township, and the cities of St. Clair and St. Clair Shores, share this spelling (see List of Michigan county name etymologies).

The name has sometimes been mistakenly attributed to honoring Patrick Sinclair, a British officer who purchased land on the St. Clair River at the mouth of the Pine River. In 1764, he built Fort Sinclair there, which was in use for nearly 20 years before being abandoned. As noted, the name was established before he was active in the area.

Geography

St. Clair County is also called the Blue Water Area.

According to the U.S. Census Bureau, the county has a total area of 837 square miles (2,170 km²), of which 721 square miles (1,870 km²) is land and 115 square miles (300 km²) (14%) is water. St. Clair County is one of five counties that form the peninsula, known as the Thumb, that projects into Lake Huron. St. Clair County is closely connected in terms of economy with its neighbors, Metro Detroit and Sanilac County in Michigan, and Lambton County across the river in Ontario, Canada. Saint Clair County is the principal county in The Blue Water Area, a sub-region of the Thumb.

Adjacent counties

• Sanilac (north)
• Lapeer (west)
• Macomb (south)
• Lambton, Ontario (east)

Major highways

• I-69 enters the county from the west, coming from Lansing and Flint, terminating at the approach to the Blue Water Bridge in Port Huron. (Once fully completed, the mainline of I-69 will span from Brownsville, Texas to Port Huron, Michigan.)
• I-94 enters St. Clair County from the southwest, having traversed the entire Metro Detroit region, and terminates at the approach to the Blue Water Bridge in Port Huron. On the Canadian side of the border, in Sarnia, Ontario, the route heads easterly, designated as Highway 402.
• BL I-69
• BL I-94
• M-19
• M-25 follows the Lake Huron–Saginaw Bay shoreline, beginning in Bay City and ending at a junction with |I-94/|I-69, and BL I-94/BL I-69 on the north side of Port Huron.
• M-29
• M-136
• M-154 serves Harsens Island, in Lake St. Clair.

Demographics

The 2010 United States census indicates St. Clair County had a 2010 population of 163,040. This is a decrease of -1,195 people from the 2000 United States census. Overall, the county had a -0.7% growth rate during this ten-year period. In 2010 there were 63,841 households and 44,238 families in the county. The population density was 226.1 per square mile (87.3 per square kilometer). There were 71,822 housing units at an average density of 99.6 per square mile (38.5 per square kilometer). 93.9% were White, 2.4% Black or African American, 0.5% Asian, 0.4% Native American, 0.7% of some other race and 2.0% of two or more races. 2.9% were Hispanic or Latino (of any race). 25.9% identified as of German, 10.2% Polish, 9.3% Irish, 8.5% English, 6.5% French, 6.5% American, and 5.1% Italian ancestry.

There were 63,841 households, out of which 31.3% had children under the age of 18 living with them, 52.9% were opposite-sex families, 11.4% had a female householder with no husband present, 30.7% were non-families, and 25.5% were made up of individuals. The average household size was 2.52 and the average family size was 3.01.

In the county, the population was spread out, with 23.7% under the age of 18, 8.0% from 18 to 24, 23.8% from 25 to 44, 30.1% from 45 to 64, and 14.5% who were 65 years of age or older. The median age was 41 years. For every 100 females, there were 98.1 males. For every 100 females age 18 and over, there were 95.7 males.

The 2010 American Community Survey 1-year estimate indicates the median income for a household in the county was $44,369 and the median income for a family was $53,207. Males had a median income of $30,056 versus $16,771 for females. The per capita income for the county was $22,390. About 10.4% of families and 15.4% of the population were below the poverty line, including 22.7% of those under the age of 18 and 6.8% of those age 65 or over.

Parks

• Algonac State Park

St. Clair County is home to five county parks: Columbus County Park, Fort Gratiot County Park, Fort Gratiot Light station, Goodells County Park, and Woodsong County Park. St. Clair County also operates the Wadhams to Avoca Trail and works with local units of government to develop the Bridge to Bay Trail.

Communities

U.S. Census data map showing local municipal boundaries within St. Clair County. Shaded areas represent incorporated cities.

Cities

• Algonac
• Marine City
• Marysville
• Memphis (partial)
• Port Huron (county seat)
• Richmond (partial)
• St. Clair
• Yale

Villages

• Capac
• Emmett

Charter townships

• China
• East China
• Fort Gratiot
• Port Huron

Civil townships

Census-designated place

• Pearl Beach

Other unincorporated communities

See also

In Spanish: Condado de St. Clair (Míchigan) para niños