Gratiot County is a county located in the geographic center of the Lower Peninsula of Michigan. Gratiot County covers 365,081 total acres in the middle of Michigan’s Lower Peninsula and consists of 16 townships that are each about 36 square miles in size. The largest cities of the area include Alma, Ithaca and St. Louis along with the villages of Breckenridge, Perrinton and Ashley.
As of the 2010 Census, the population was 42,476. The county seat is Ithaca, although its most populous city is Alma.
Gratiot County comprises the Alma, MI Micropolitan Statistical Area, which is also included in the Mount Pleasant- -Alma, MI Combined Statistical Area. The county is named for Captain Charles Gratiot, who supervised the building of Port Huron’s Fort Gratiot. It was set off in 1831; organized in 1855. Gratiot County was a New England settlement. The original founders of Ithaca and of Alma consisted entirely of settlers from New England. These people were "Yankee’s", that is to say they were descended from the English Puritans who settled New England in the 1600s.