[4] Harrison Township was formed in 1827 in the Michigan Territory along the shores of Lake St. Clair.

[7] The township is in southeastern Macomb County, along the northwestern shores of Lake St. Clair.

The township is partially bordered to the west by the city of Mount Clemens, the Macomb county seat.

[3] Selfridge Air National Guard Base, which was first built in 1917, is an Air National Guard installation that occupies a large portion of the northern section of the township.

33.1% of all households were made up of individuals, and 8.2% had someone living alone who was 65 years of age or older.