Kalamazoo is the largest city in the southwest region of the U.S. state of Michigan. It is the county seat of Kalamazoo County. As of the 2000 census, the city ha a total population of 77,145. The 2006 Census Bureau estimate placed the city at a total population of 72,161. It is the major city of the Kalamazoo-Portage, MI MSA, which had an estimated population of 323,264 as of 2007.