Bay County is located in the U.S. state of Michigan. As of the 2020 Census, the population was 103,856. The county seat is Bay City. Bay County comprises the Bay City, MI Metropolitan Statistical Area and is included in the Saginaw-Midland-Bay City Combined Statistical Area in the Mid/Central Michigan region.
History
19th century
Bay County was created in 1857 from portions of Midland County, Saginaw County, and Arenac County. Its name references that it "surrounds Saginaw Bay."
20th century
During World War II, shipyards in Bay County were used to produce US Destroyers and missile vessels.
In 1978, Bay County became the second Michigan county (after Oakland County) to adopt a County Executive form of government. Act 139 of 1973 provides for an optional unified form of county government under an appointed County Manager or an elected County Executive. With the County Executive, all departments of the county government that are not headed by a separate elected official (e.g. Treasurer, Clerk, Sheriff, etc.) are under the direction of the County Executive. The County Executive also has veto power over the motions and resolutions passed by the County Commission.
Geography
According to the U.S. Census Bureau, the county has a total area of , of which is land and (30%) is water. It is the fifth-smallest county in Michigan by land area.
The Saginaw River flows through Bay City while the Kawkawlin River drains much of the central portion of the county. The Pinconning River and Saganing Creek drain the northern portion. The Saginaw Bay of Lake Huron lies to the east, giving the county its name.
Major highways
- in Midland
Interstate 75 (I-75) and U.S. Highway 23 (US 23), which are concurrent within the county, are the major north–south route. North of Bay City, M-13 follows a parallel route a few miles to the east. US 10 has its eastern terminus in Bay City. M-25, M-15, and M-84 enter Bay City from the east, southeast and southwest respectively and terminate in or near the city. M-20 and Business US 10 end at US 10 as they enter the county.
Adjacent counties
upright|thumb|Bay County in 1873; a decade later [[Arenac County, Michigan|Arenac County was organized from the northern townships seen in this map.]]
- Arenac County (north)
- Gladwin County (northwest)
- Tuscola County (southeast)
- Midland County (west)
- Saginaw County (south)