Bay City is a city in the U.S. state of Michigan located near the base of the Saginaw Bay on Lake Huron. As of the 2000 census, the city's population was 36,817, with the 2008 census estimate placing the population at 33,874. It is the county seat of Bay County and is the principal city of the Bay City Metropolitan Statistical Area, which is included in the Saginaw-Bay City-Saginaw Township North Combined Statistical Area. The city, along with nearby Midland and Saginaw, form the "Tri-Cities" region. The city is geographically divided by the Saginaw River, and travel between the east and west sides of the city is made possible by four modern drawbridges which allow large ships to travel easily down the river. The city is served by MBS International Airport, located in nearby Freeland, and James Clements Municipal Airport.