Which of these cities is not a part of the Greater Tri-Cities of Michigan?

The name Tri-Cities refers to two regions in the U.S. state of Michigan. Both are located in the Lower Peninsula.

The larger and more well known Tri-Cities is the region surrounding the cities of Saginaw, Bay City, and Midland. This region, which is also considered to be part of the Central Michigan, includes much of Bay County, Saginaw County, and Midland County. These three counties make up the Greater Tri Cities, a common term describing this region of Michigan. As of recently, the region also goes by the name of the Great Lakes Bay Region.

Mount Pleasant is not one of the Greater Tri Cities of Mitchigan. It is a city in the U.S. state of Michigan. Located in Central Michigan, the city is the county seat of Isabella County. Part of the city is located within the Isabella Indian Reservation, the base of the federally recognized Saginaw Chippewa Tribal Nation. The tribe's Soaring Eagle Casino & Resort in nearby Chippewa Township is also within the reservation boundaries.