Grant County, Wisconsin

Grant County is a county in Wisconsin, United States, about 19 miles east of Dubuque, Iowa,
across the Mississippi River. It had a population of 51,938 at the 2020 census, an estimated
52,446 in 2025, and covers 1,147 square miles (2,970 km2) of land centred near 42°52′N 90°43′W.

Lancaster is the county seat; its postal code is 53813. The county holds 5 cities, 14
villages and 38 unincorporated communities across 33 towns, and it runs on Central Time. Its
FIPS code is 55043.

Towns & Villages in Grant County

Grant County has 19 incorporated places on record: 5 cities and 14 villages. It also carries
38 named unincorporated communities with no local government of their own, listed further below.
CDP stands for census designated place; Unincorp. covers crossroads and rural communities with
no formal boundary.

Three villages sit on a county line. Cuba City is mostly in Grant County but reaches into
Lafayette County; Hazel Green does the same, with a small share in Lafayette County; and
Muscoda, Livingston and Montfort each carry the bulk of their population in Grant County with a
smaller share across the Iowa County line. Populations above are village-wide totals, not
Grant-County-only counts.

Beyond the 19 incorporated places, Grant County lists 38 unincorporated communities: Annaton,
Arthur, Beetown, Bigpatch, British Hollow, Brodtville, Buena Vista, Burton, Castle Rock,
Centerville, Cornelia, Diamond Grove, Ellenboro, Elmo, Fair Play, Five Points, Flora Fountain,
Georgetown, Glen Haven, Hickory Grove, Homer, Hurricane, Lancaster Junction, Louisburg,
McCartney, Millville, Mount Ida, North Andover, Prairie Corners, Preston, Rockville, Rutledge,
Saint Rose, Sandy Hook, Shady Dell, Sinsinawa, Stitzer, Union, Van Buren, Werley and Wyalusing.
None has a 2020 census count of its own; the Census Bureau does not track population separately
for a place with no incorporated boundary.

Towns

Wisconsin organizes its rural land into civil towns rather than survey townships, and Grant
County has 33 of them: Beetown, Bloomington, Boscobel, Cassville, Castle Rock, Clifton,
Ellenboro, Fennimore, Glen Haven, Harrison, Hazel Green, Hickory Grove, Jamestown, Liberty,
Lima, Little Grant, Marion, Millville, Mount Hope, Mount Ida, Muscoda, North Lancaster, Paris,
Patch Grove, Platteville, Potosi, Smelser, South Lancaster, Waterloo, Watterstown, Wingville,
Woodman and Wyalusing. Each town runs its own elected board and provides road maintenance,
zoning and fire protection outside the incorporated cities and villages; several share a name
with the village or city inside their boundary (the Town of Fennimore surrounds the City of
Fennimore, for example), while others, like Clifton, Harrison, Liberty, Lima, Little Grant,
Marion, Paris, Smelser, Waterloo, Watterstown and Wingville, contain no incorporated place at
all.

ZIP Codes

• 53818 — Platteville
• 53813 — Lancaster
• 53805 — Boscobel
• 53809 — Fennimore
• 53807 — Cuba City
• 53811 — Hazel Green
• 53573 — Muscoda
• 53820 — Potosi
• 53806 — Cassville
• 53518 — Blue River
• 53804 — Bloomington
• 53554 — Livingston
• 53801 — Bagley
• 53569 — Montfort
• 53808 — Dickeyville
• 53816 — Mount Hope
• 53827 — Woodman
• 53810 — Glen Haven
• 53825 — Stitzer
• 53812 — Kieler
• 53817 — Patch Grove
• 53802 — Beetown
• 53824 — Sinsinawa

Tennyson has no ZIP code of its own; mail there goes through the Cuba City post office.
Kieler, Stitzer, Sinsinawa and Glen Haven have their own delivery ZIP but no separate
incorporated boundary — each is an unincorporated community large enough to have kept a
post office. The remaining unincorporated communities are served by the nearest town’s code.

Geography

Grant County sits in the unglaciated Driftless Area of southwestern Wisconsin, a landscape of
steep ridges and narrow valleys that the last ice age skipped over. The Mississippi River forms
the county’s entire western border, and the Wisconsin River marks most of its northern edge
before the two rivers meet at the county’s northwest corner near Wyalusing. The Grant River,
which gives the county its name, runs south through the middle of the county to join the
Mississippi near Potosi. Of the county’s 1,183 square miles, 1,147 are land and 36 are water,
about 3 percent, concentrated along the two big rivers.

Crawford County lies to the north, Richland County to the northeast, Iowa County to the east,
and Lafayette County to the southeast. Across the Mississippi to the west and southwest are Jo
Daviess County, Illinois, Dubuque County, Iowa, and Clayton County, Iowa. Crawford County, Richland County, Iowa County, Lafayette County, Jo Daviess County, Dubuque County and Clayton County all border Grant
County directly.

Demographics

Grant County had a population of 51,938 at the 2020 census, and the latest estimate puts the
county near 52,446 residents. Platteville and Lancaster are the two largest communities;
Platteville alone holds nearly a quarter of the county’s population, driven in large part by the
University of Wisconsin–Platteville student body. Median household income runs $66,858
(2024 ACS), below Wisconsin’s statewide figure of $74,631 (2023 ACS). Population density works
out to roughly 46 people per square mile of land, low even by rural Wisconsin standards, and the
lowest among counties along this stretch of the Mississippi.

Economy & Local Life

Manufacturing employs the most workers in the county, about 3,942 people, followed by retail
trade at 3,797 and health care and social assistance at 3,077. The University of
Wisconsin–Platteville, with its long-running engineering and mining-engineering programs,
is Platteville’s largest single employer and anchors the city’s economy. Lancaster’s Grant
County Courthouse, topped by an octagonal glass-and-copper dome completed in 1905, houses the
county government and gives Lancaster its nickname, the City of the Dome. Boscobel is home to
the Wisconsin Secure Program Facility, a state prison that is one of the county’s larger
employers outside the two college and county-seat towns. Potosi holds the National Brewery
Museum inside the restored Potosi Brewing Company building on the old brewery site, and the
village runs an annual Catfish Festival each summer, drawing visitors from across the tri-state
area.

History

Wisconsin’s territorial legislature created Grant County in 1837, naming it for the Grant
River, which was itself named for an early fur trader whose full history is not recorded. Lead
mining drew the county’s first wave of settlers in the 1820s and 1830s, and the lead and zinc
industry shaped Platteville and the surrounding towns for nearly a century. Lancaster, platted
in 1837 by land speculator Glendower M. Price and named after Lancaster, Pennsylvania at a
relative’s suggestion, became the county seat and is the boyhood home of Nelson Dewey,
Wisconsin’s first state governor. Pleasant Ridge, just outside Lancaster, was founded in 1849 by
the Shepard family and is remembered as one of Wisconsin’s earliest African-American farming
settlements.

Getting There

No interstate highway crosses Grant County. U.S. Routes 18, 61 and 151 run through it, along
with Wisconsin State Routes 11, 35, 80, 81, 129 and 133.

• Dubuque, Iowa — about 19 miles west of Platteville
• Madison — about 59 miles northeast of Platteville
• Galena, Illinois — about 22 miles south of Platteville
• Dodgeville — about 24 miles northeast of Platteville

Southwest Wisconsin Regional Airport in Dubuque no longer runs scheduled airline service, so
Dane County Regional Airport in Madison is the nearest airport with commercial flights. Several
county towns keep their own general-aviation fields, including Platteville Municipal, Lancaster
Municipal, Cassville Municipal and Boscobel Municipal. Amtrak has no station in Grant County; the
nearest stop on the Empire Builder line is in La Crosse.

Frequently Asked Questions

Where is Grant County located?
It sits in Wisconsin’s unglaciated Driftless Area, in the state’s far southwest corner, bordered
by the Mississippi River to the west and the Wisconsin River along much of its north side.

What is the population of Grant County?
51,938 at the 2020 census, with a 2025 estimate near 52,446.

How big is Grant County?
1,147 square miles (2,970 km2) of land, plus 36 square miles of water.

What is the county seat of Grant County?
Lancaster is the county seat, home to the Grant County Courthouse and its distinctive dome.

How many towns and villages are in Grant County?
Five cities — Platteville, Lancaster, Boscobel, Fennimore and Cuba City — plus 14
villages, spread across 33 civil towns, along with 38 unincorporated communities.

What ZIP codes does Grant County use?
23 ZIP codes in all, led by 53818 for Platteville, 53813 for Lancaster, 53805 for Boscobel and
53809 for Fennimore.

What is Grant County known for?
Lead and zinc mining history, the University of Wisconsin–Platteville, the Potosi Brewing
Company and National Brewery Museum, and its position in the Driftless Area along the
Mississippi River.

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