By land By water The 2010 United States census indicated Keweenaw County had a population of 2,156.

[3] At the 2010 census, 98.5% of the population were White, 0.1% Black or African American, 0.1% Native American and 1.2% of two or more races; a total of 0.7% were Hispanic or Latino (of any race); of them, 28.8% were of Finnish, 14.0% German, 9.0% English, 6.6% French, French Canadian or Cajun and 5.7% Irish ancestry.

[18] Keweenaw County was solidly Republican after the American Civil War, and until the Franklin Delano Roosevelt era.

The county government operates the jail, maintains rural roads, operates the major local courts, records deeds, mortgages, and vital records, administers public health regulations, and participates with the state in the provision of social services.

The county board of commissioners controls the budget and has limited authority to make laws or ordinances.

In Michigan, most local government functions—police and fire, building and zoning, tax assessment, street maintenance, etc.—are the responsibility of individual cities and townships.

The Keweenaw County Courthouse and Sheriff's Residence and Jail in Eagle River faces Lake Superior.

In her book Buildings of Michigan, Eckert writes:[24] The courthouse still preserves its original appearance.