Carson City is a city in Montcalm County of the U.S. state of Michigan. As of the 2000 census, the city population was 1,190. Carson City was first platted in 1866 on land owned by R. M. Abbott, Delia Miner, and Hiram T. Sherman and recorded in 1871. The first lot was sold to Thomas Scott and two nephews, John and Thomas LaDue in 1867. With the corporate name Scott & LaDue, they built a sawmill in 1868 and a grist mill in 1870. The post office from North Shade in Gratiot County was transferred here on August 3, 1868, with Hiram T. Sherman as the first postmaster. The name Carson City was given to the post office by Thomas Scott, who had been in Carson City, Nevada, during the gold and silver mining boom days. Carson City incorporated as a village in 1887 and as a city in 1960. The first mayor of Carson city was John T Hallett. He was resided at 322 e main st, the house is still there and owned by elton c jason... The Carson City post office, with ZIP code 48811, serves most of Bloomer Township and southern portions of Crystal Township in Montcalm County and the western portions of North Shade Township and southwestern New Haven Township in Gratiot County.