Bay County is a county in Michigan, United States, on the shore of Saginaw Bay in the east-central Lower Peninsula. It had a population of 103,856 at the 2020 census and covers 631 square miles (1,630 km2), centred near 43°43′N 83°56′W.
Bay City is the county seat, and its postal code is 48706. Bay County contains four cities — Auburn, Bay City, Essexville and Pinconning, plus a small partial portion of Midland — fourteen charter and civil townships, and dozens of unincorporated communities along Saginaw Bay. The county lies in the Eastern time zone.
Towns & Villages in Bay County
Bay County has four incorporated cities and about thirty unincorporated communities and beach settlements, most of them clustered along the Saginaw Bay shoreline or the Saginaw River. Bay City, Essexville, Pinconning and Auburn are self-governing cities; everywhere else listed below is an unincorporated place (Unincorp.) inside one of the county’s townships. A small edge of the city of Midland, whose main body sits in neighboring Midland County, also crosses into Bay County.
| Place | Type | Pop. | ZIP |
|---|---|---|---|
| Bay City | City · seat | 32,661 | 48706 |
| Essexville | City | — | 48732 |
| Pinconning | City | — | 48650 |
| Auburn | City (partial) | — | 48611 |
| Midland | City (partial) | — | — |
| Almeda Beach | Unincorp. | — | — |
| Amelith | Unincorp. | — | — |
| Aplin Beach | Unincorp. | — | — |
| Arn | Unincorp. | — | — |
| Beaver | Unincorp. | — | — |
| Bentley | Unincorp. | — | 48613 |
| Brissette Beach | Unincorp. | — | — |
| Brooks | Unincorp. | — | — |
| Crump | Unincorp. | — | — |
| Donahue Beach | Unincorp. | — | — |
| Duel | Unincorp. | — | — |
| Fisherville | Unincorp. | — | — |
| Frankenlust | Unincorp. | — | — |
| Kawkawlin | Unincorp. | — | 48631 |
| Killarney Beach | Unincorp. | — | — |
| Lagoon Beach | Unincorp. | — | — |
| Linwood | Unincorp. | — | 48634 |
| Linwood Beach | Unincorp. | — | — |
| Little Killarney Beach | Unincorp. | — | — |
| Loehne | Unincorp. | — | — |
| Meyers Beach | Unincorp. | — | — |
| Mount Forest | Unincorp. | — | — |
| Munger | Unincorp. | — | 48747 |
| Nine Mile | Unincorp. | — | — |
| North Williams | Unincorp. | — | — |
| Seidlers | Unincorp. | — | — |
| Three Churches Corner | Unincorp. | — | — |
| Tobico Beach | Unincorp. | — | — |
| University Center | Unincorp. | — | 48710 |
| Willard | Unincorp. | — | — |
| Woodville | Unincorp. | — | — |
University Center straddles the Bay, Saginaw and Tuscola county lines and is best known as the home of Delta College and Saginaw Valley State University. Munger sits close to the Bay–Tuscola county line, and several of the “Beach” hamlets — Almeda Beach, Aplin Beach, Donahue Beach, Killarney Beach, Little Killarney Beach, Linwood Beach, Meyers Beach and Tobico Beach — are small seasonal shoreline subdivisions on Saginaw Bay rather than separately governed places.
Townships
| Township | Pop. (2020) | Main settlements |
|---|---|---|
| Bangor Charter Township | — | — |
| Beaver Township | — | Beaver |
| Frankenlust Township | — | Frankenlust, University Center |
| Fraser Township | — | — |
| Garfield Township | — | Munger |
| Gibson Township | — | Willard |
| Hampton Charter Township | — | — |
| Kawkawlin Township | — | Kawkawlin |
| Merritt Township | — | Amelith |
| Monitor Charter Township | — | — |
| Mount Forest Township | — | Mount Forest |
| Pinconning Township | — | surrounds the city of Pinconning |
| Portsmouth Charter Township | — | — |
| Williams Charter Township | — | North Williams, Three Churches Corner |
ZIP Codes
- 48706 — Bay City
- 48708 — Bay City
- 48707 — Bay City (PO Box only)
- 48732 — Essexville
- 48650 — Pinconning
- 48611 — Auburn
- 48634 — Linwood
- 48631 — Kawkawlin
- 48747 — Munger
- 48613 — Bentley
- 48710 — University Center
Most of the county’s small beach hamlets and rural crossroads — places like Beaver, Crump, Duel and the shoreline “Beach” communities — are served by the nearest post office town’s ZIP code rather than one of their own.
Geography
Bay County sits on the flat lake plain at the foot of Saginaw Bay, an arm of Lake Huron, and the Saginaw River crosses the county to empty into the bay at Bay City. The county’s 631 square miles split 442 square miles of land and 188 square miles of water — about 30% of the total — making it Michigan’s fifth-smallest county by land area but one of its largest by water. The terrain is nearly level farmland and marsh, with the shoreline itself given over to cottages, marinas and wildlife areas such as the Tobico Marsh unit of Bay City State Recreation Area.
Bay County borders Arenac County to the north, Gladwin County to the northwest, Midland County to the west, Saginaw County to the south, and Tuscola County to the southeast. All five neighbors have their own Arenac, Gladwin, Midland, Saginaw and Tuscola county profiles on this site.
Demographics
Bay County had 103,856 residents at the 2020 census, giving it a density of roughly 235 people per square mile of land. Bay City, the county seat, is by far the largest community at 32,661 people; Essexville is the county’s second-largest city, though its exact 2020 count is not separately confirmed here. Median household income in Bay County runs below the Michigan median of $69,183, reflecting the county’s manufacturing- and agriculture-based economy relative to the state as a whole.
Economy & Local Life
Health care, chemicals and agribusiness anchor the local economy. McLaren Bay Region is the county’s largest employer, followed by Dow Chemical, Delta College and Michigan Sugar Company, which processes sugar beets grown across the Saginaw Valley. Bay City’s revived downtown and riverfront, centered on Saginaw Street and the Uptown district on the former Chrysler foundry site, is the county’s main commercial and entertainment hub, and the Saginaw Bay waterfront supports boating, fishing and seasonal tourism throughout Bangor, Hampton and Portsmouth townships.
History
Bay County was organized on February 17, 1857, carved from portions of Midland, Saginaw and Arenac counties, and takes its name from Saginaw Bay, which forms its eastern boundary. Bay City grew rapidly in the 19th century as a Great Lakes lumber and shipbuilding port before the pine forests were exhausted, then diversified into sugar-beet processing, coal mining and, later, automotive parts manufacturing. West Bay City, on the river’s west bank, was a separate city until it consolidated with Bay City in 1905.
Getting There
Interstate 75 and US Route 23 run north–south through the county, and US Route 10 terminates in downtown Bay City.
- Saginaw — about 20 miles south via I-75
- Midland — about 20 miles west via US-10
- Flint — about 60 miles south via I-75
- Detroit — about 105 miles south via I-75
The nearest commercial airport is MBS International Airport in Freeland, roughly 15 miles southwest of Bay City.
Frequently Asked Questions
Where is Bay County, Michigan?
It is on Saginaw Bay in the east-central Lower Peninsula, about 100 miles north of Detroit.
What is the population of Bay County?
103,856 at the 2020 census.
How big is Bay County?
631 square miles (1,630 km2), of which 442 square miles are land and 188 square miles are water.
What is the county seat of Bay County?
Bay City, which is also the county’s largest city.
How many towns are in Bay County?
Four incorporated cities — Bay City, Essexville, Pinconning and Auburn — plus about thirty unincorporated communities and a small partial edge of Midland.
What ZIP codes are in Bay County?
Mainly 48706–48708 (Bay City), 48732 (Essexville), 48650 (Pinconning), 48611 (Auburn), 48631 (Kawkawlin), 48634 (Linwood), 48613 (Bentley), 48747 (Munger) and 48710 (University Center).
Why is it called Bay County?
It is named for Saginaw Bay, the Lake Huron inlet that forms its eastern edge.
More counties in this state: Towns and villages in Michigan.