Monroe County, Michigan

Monroe County is a county in Michigan, United States, on Lake Erie about 35 miles south of
Detroit, along the Michigan-Ohio line. It had a population of 154,809 at the 2020 census, an
estimated 156,004 by 2025, and covers 549 square miles (1,422 km2) of land centred near
41°55′N 83°30′W.

Monroe is the county seat and largest city; its postal code is 48161. The county holds 3
cities, 5 incorporated villages and 8 census-designated places spread across 15 townships, and
it runs on Eastern Time. Its FIPS code is 26115.

Towns & Villages in Monroe County

Monroe County has 16 incorporated and census-recognized communities on record, plus dozens of
smaller rural hamlets with no local government of their own. CDP stands for census designated
place — a statistically defined community with no mayor or town council.

Cities in Michigan sit outside township government, so the Township column reads
— for Monroe, Luna Pier and Petersburg. Two more cities touch the county only at the
edge: Flat Rock (2020 population 10,541) lies mostly in Wayne County with a sliver in Ash
Township, and Milan (2020 population 6,079) sits mostly in Washtenaw County with its
northwestern edge in Milan Township — neither city’s population is counted toward
Monroe County’s incorporated total above.

Eight more communities are census-designated places, unincorporated but populous enough for
the Census Bureau to track separately:

Beyond the sixteen places above, county gazetteers list roughly three dozen smaller
unincorporated hamlets and crossroads with no Census population or ZIP code of their own,
among them Avalon Beach, Azalia, Bolles Harbor, Cone, Diann, Erie, Evergreen Acres, Golfcrest,
Grand View, Grape, Hillcrest Orchard, Ida Center, La Salle, Liberty Corners, London, Lost
Peninsula, Lulu, Newport, North Shores, Oakville, Oldport, Ottawa Lake, Patterson Gardens,
Petersburg Junction, Pointe aux Peaux, Rea, Saint Anthony, Samaria, Scofield, Steiner, Stony
Creek, Strasburg, Vienna, Whiteford Center and Yargerville.

Townships

Michigan divides every county into civil townships that provide local government outside the
incorporated cities and villages. Monroe County has 15 townships, ranked here by 2020
population.

ZIP Codes

• 48161 and 48162 — Monroe, South Monroe, West Monroe and Detroit Beach
• 48144 — Lambertville
• 48182 — Temperance
• 48131 — Dundee
• 48117 — Carleton
• 48179 — South Rockwood
• 48166 — Newport, Estral Beach, Woodland Beach and Stony Point
• 48140 — Ida
• 48159 — Maybee
• 48157 — Luna Pier
• 48133 — Erie
• 48177 — Samaria
• 49270 — Petersburg
• 49267 — Ottawa Lake

Estral Beach, Woodland Beach and Stony Point have no post office of their own and share
Newport’s 48166 ZIP code; several of the rural hamlets listed above use a neighbor’s ZIP for
the same reason.

Geography

Monroe County covers 680 square miles in total, 549 square miles (1,422 km2) of it land and
131 square miles (340 km2) of it water — the water share is almost entirely Lake Erie,
which forms the county’s eastern edge. Monroe is the only Michigan county touching Lake Erie.
The River Raisin crosses the county west to east and empties into the lake at the city of
Monroe. Sterling State Park, on the Frenchtown Township shoreline, is the only state park on
Michigan’s Lake Erie coast.

Monroe County borders Wayne
County to the northeast, Washtenaw
County to the northwest, Lenawee
County to the west, and Lucas County, Ohio to the south.
Essex County, Ontario, Canada lies directly east across Lake Erie.

Demographics

Monroe County had a population of 154,809 at the 2020 census and an estimated 156,004 by 2025.
Its largest city is Monroe at 20,462, and its largest township is Bedford Township at 31,813,
driven by the Lambertville and Temperance communities along the Ohio line. Median household
income was $77,335 in a 2024 estimate, above Michigan’s statewide median of $69,183 (2023 ACS).
Population density is about 282 people per square mile of land.

Economy & Local Life

Manufacturing is the county’s largest employment sector with 14,259 workers, followed by
health care and social assistance at 10,853 and retail trade at 7,240, out of roughly 71,685
total jobs countywide. La-Z-Boy, the furniture maker, was founded in Monroe in 1927 and still
keeps its world headquarters in the city. ProMedica Monroe Regional Hospital is the county’s
largest single employer, and DTE Energy runs the Monroe Power Plant, one of the largest
coal-fired plants in the United States at 3,280 megawatts, alongside the Enrico Fermi Nuclear
Station in Frenchtown Township. Monroe County Community College, founded in 1964, is the
county’s only public higher-education institution. Every January, River Raisin National
Battlefield Park in Monroe holds a memorial service commemorating the soldiers who fought at
the Battle of Frenchtown.

History

Monroe County was organized July 14, 1817, the second county formed in Michigan Territory
after Wayne County. It was named for President James Monroe ahead of a planned visit. The
county was originally much larger; its western portion split off to form Lenawee County in
1826. On January 18 and 22, 1813, American forces under General James Winchester fought
British and Indigenous forces at Frenchtown on the River Raisin, in what is now the city of
Monroe. British-allied warriors killed a large number of wounded American prisoners after the
battle, an event remembered as the River Raisin Massacre and the deadliest recorded battle on
Michigan soil.

Getting There

Interstate 75 runs north-south through the eastern half of the county, connecting Monroe
directly to Detroit and Toledo; US Route 24 and US Route 23 serve the western townships. No
interstate crosses the county’s western half.

• Detroit — 35 miles north
• Toledo, Ohio — 20 miles south
• Ann Arbor — 30 miles northwest
• Adrian — 25 miles west

Detroit Metropolitan Wayne County Airport is the nearest major commercial airport. Amtrak
does not serve Monroe County; the closest station is in Toledo, Ohio.

Frequently Asked Questions

Where is Monroe County, Michigan?
It is in southeastern Michigan on Lake Erie, about 35 miles south of Detroit and 20 miles
north of Toledo, Ohio.

What is the population of Monroe County?
154,809 at the 2020 census, estimated at 156,004 by 2025.

How big is Monroe County?
549 square miles (1,422 km2) of land plus 131 square miles (340 km2) of Lake Erie water,
680 square miles total.

What is the county seat of Monroe County?
Monroe is the county seat and the county’s largest city.

How many towns and villages are in Monroe County?
Sixteen incorporated cities, villages and census-designated places, plus about three dozen
smaller unincorporated hamlets, spread across 15 townships.

What ZIP codes cover Monroe County?
Fourteen main ZIP codes are in use, led by 48161 and 48162 for Monroe; the full list is above.

What happened at the Battle of Frenchtown?
In January 1813, American forces were defeated at Frenchtown on the River Raisin, and the
killing of wounded prisoners afterward became known as the River Raisin Massacre —
the deadliest battle recorded on Michigan soil.

More counties in this state: Towns
and villages in Michigan.