St. Clair County

county

St. Clair County, Michigan

Overview

Geography

Region: The Thumb/Blue Water Area
Total Area: 837 sq mi
Land Area: 721 sq mi
Water Area: 115 sq mi
Latitude: 42.93
Longitude: -82.67
Climate: St. Clair County experiences a mild climate with warm summers and cold winters. The average high temperature in the summer is typically in the mid-seventies (°F) while the winter months bring temperatures in the twenties or lower (°F). The area receives an average of three feet of snowfall each year, though it can often exceed this amount. The county also receives an average of 34 inches of rain annually.
Notable Features: St. Clair River · Lake St. Clair · Lake Huron · Pine River
Neighboring Areas: Sanilac County (north) · Lapeer County (west) · Macomb County (south) · Lambton, Ontario (east)

Demographics

Population (2020): 160,383
Est. Population (2026): 160,364
Median Age: 44.5
Median Income: $69,349
Family Households: 66.9%
Racial & Ethnic Composition: The racial makeup of the county was 90.1% White, 2.5% Black or African American, 0.4% American Indian and Alaska Native, 0.5% Asian, <0.1% Native Hawaiian and Pacific Islander, 0.9% from some other race, and 5.6% from two or more races. Hispanic or Latino residents of any race comprised 3.4% of the population.

Governance

Government Type: County Commission
Governing Body: Board of Commissioners
Municipal Services: Jail operation · Rural road maintenance · Major local court operation · Deed and mortgage filing · Vital record maintenance · Public health regulation administration · Welfare and social service participation with the state

Economy

Unemployment Rate: 5%
Economic Profile: Diversified: Manufacturing, Healthcare, Retail, Education
Employment Sectors: Manufacturing · Health Care & Social Assistance · Retail Trade · Education

Education

School Districts: Algonac Community Schools · Capac Community Schools · East China Schools · Marysville Public Schools · Memphis Community Schools · Port Huron Schools · Yale Public Schools
Colleges & Universities: St. Clair County Community College

Infrastructure

Transportation: I-94 · I-69 · M-25 · M-154 · Amtrak (Blue Water train) · Blue Water Bridge
Utilities: Municipal water · Fiber/broadband
Major Facilities: St. Clair County International Airport

Recreation

Outdoor Access: Yes
Major Recreation Areas: Goodells County Park · Columbus County Park · Fort Gratiot County Park · Woodsong County Park · Fort Gratiot Light Station · Blue Water River Walk County Park · Marine City Dredge Cut · Wadhams to Avoca Trail · North Channel County Park · Bridge to Bay Trail
Parks & Trails: County Parks · Wadhams to Avoca Trail · Bridge to Bay Trail

History

Founded: 1820
Incorporated: 1821
Named After: Lake St. Clair/St. Clair River, named by French explorer René-Robert Cavelier, Sieur de La Salle after Saint Clare of Assisi
Historical Significance: Located in Michigan's Thumb region, bordering the St. Clair River and Lake Huron, the county has played a significant role in maritime history and Great Lakes commerce.
Key Events: County created from Macomb County in 1820 · Government organized in 1821 · County seat moved to Port Huron in 1871