Harrison is a city in and county seat of Clare County in the U.S. state of Michigan. The population was 2,150 at the 2020 census. The commu…Harrison is a city in and county seat of Clare County in the U.S. state of Michigan. The population was 2,150 at the 2020 census. The community was settled as early as 1877 and was named after William Henry Harrison. Harrison is near the junction of US 127 and M-61. US 127 bypasses the city to the east, while Bus. US 127 runs through the center of the city. Wilson State Park and Budd Lake are located within the city.