Dubuque County, Iowa

Dubuque County is a county in Iowa, United States, on the Mississippi River where Iowa, Illinois
and Wisconsin meet. It had a population of 99,266 at the 2020 census, an estimated 99,381 by 2025,
and covers 616.46 square miles (1,596.6 km2) centred near 42°28′N 90°53′W.

Dubuque is the county seat and by far the county’s largest city; its postal code is 52001.
The county holds 21 incorporated cities and 12 unincorporated communities across 18 townships, and
it runs on Central Time. Its FIPS code is 19061.

Towns & Villages in Dubuque County

Dubuque County has 33 named places on record: 21 incorporated cities, one of them the county
seat, and 12 unincorporated communities with no local government of their own. Iowa law does not
distinguish “towns” from “cities” — every incorporated place here is
legally a city, whatever its size. Unincorp. covers crossroads and rural communities with no
formal boundary.

Two places on this list straddle county lines. Cascade sits mostly in Dubuque County but its
south side reaches into Jones County, so its 2,386 residents include some Jones County addresses.
Zwingle runs the same way into Jackson County to the south. A third pair is easy to confuse on the
page alone: Balltown, an incorporated city on the Great River Road, is a separate place from Old
Balltown, an unincorporated hamlet nearby that predates it.

Townships

Dubuque County is divided into 18 civil townships, which still run cemeteries, township roads
and local elections in Iowa even where a city has since taken over most services. Four have a
recorded population, all from the 2000 census, the last year the county reported township-level
figures separately: Center Township — covering Asbury, Centralia and Graf plus the hamlets
of Budd, Five Points, Lattnerville, Lore and Twin Springs — had 1,726 residents; Dodge
Township — covering Worthington and parts of Dyersville and Farley — had 1,204;
Cascade Township — covering part of the city of Cascade — had 1,079; and Concord
Township — covering Holy Cross, part of Rickardsville and the hamlet of Cottage Hill —
had 830. The other 14 townships — Dubuque, Iowa, Jefferson, Julien, Liberty, Mosalem, New
Wine, Peru, Prairie Creek, Table Mound, Taylor, Vernon, Washington and Whitewater — carry no
separately reported population and are mostly farmland between the incorporated cities.

ZIP Codes

• 52001 — Dubuque (also covers Sageville)
• 52002 — Asbury
• 52040 — Dyersville
• 52033 — Cascade
• 52045 — Epworth (also serves Bankston)
• 52068 — Peosta (also serves Centralia)
• 52046 — Farley
• 52065 — New Vienna
• 52078 — Worthington
• 52053 — Holy Cross
• 52056 — Luxemburg
• 52073 — Sherrill (also serves Balltown)
• 52032 — Bernard
• 52079 — Zwingle
• 52039 — Graf and Durango share this code

Rickardsville has no ZIP code of its own; mail there is delivered under Epworth’s 52045.
The twelve unincorporated communities — Ballyclough, Bennettsville, Center Grove, Fillmore,
Five Points, Key West, Massey, Old Balltown, Rockdale, Shawondasse, Waupeton and Washington Mills
— likewise carry the ZIP of whichever incorporated city sits nearest.

Geography

Dubuque County sits in northeastern Iowa’s driftless region, a hilly, unglaciated
landscape of bluffs and river valleys unlike the flat farmland typical of most of the state. Of
its 616.46 square miles, 608.30 are land and 8.16 are water, about 1.3 percent. The Mississippi
River forms the county’s northeastern and eastern edge, and the north and south forks of the
Maquoketa River drain the county’s interior before joining farther south. The bluffs along
the Mississippi near Dubuque rise several hundred feet above the river, among the highest points
in Iowa.

Clayton County lies to the north, Grant County, Wisconsin and Jo Daviess County, Illinois lie
across the Mississippi to the northeast and east, Jackson County lies to the southeast, Jones
County to the southwest, and Delaware County to the west. Clayton County, Grant County, Jo Daviess County, Jackson County, Jones County and Delaware County all border Dubuque
directly.

Demographics

Dubuque County had a population of 99,266 at the 2020 census, up from 93,653 in 2010, and the
latest estimate puts the county near 99,381 residents. Dubuque and Asbury are by far the two
largest communities, together holding roughly two-thirds of the county’s population. Median
household income runs about $77,630 as of 2024, above Iowa’s statewide 2023 figure of
$71,433. Population density works out to about 163 people per square mile of land, concentrated
heavily around the city of Dubuque and its immediate suburbs of Asbury and Peosta.

Economy & Local Life

Manufacturing employs the most workers in the county, about 8,893 people, followed by health
care and social assistance at 7,478 and retail trade at 5,992. John Deere’s Dubuque Works
plant, which builds construction and forestry equipment, is the county’s largest private
manufacturing employer. Flexsteel Industries and Georgia-Pacific also run major plants in Dubuque,
and Mercy Medical Center and UnityPoint Health’s Finley Hospital anchor the health care
sector. Dyersville, in the county’s northwest, markets itself as the “Farm Toy Capital
of the World” and hosts the National Farm Toy Museum along with farm toy shows each June and
November; the Field of Dreams movie site and ballpark sit just outside town. Dubuque’s
biggest annual event is the Julien Dubuque Film Festival each April, which draws filmmakers and
audiences from across the Midwest.

History

Dubuque County was organized on 1 October 1834, one of the first two counties established in
what later became Iowa Territory. It is named for Julien Dubuque, a French-Canadian trader who
settled near the site in 1788 and mined lead along the Mississippi with the permission of the Meskwaki,
becoming the first documented European resident of present-day Iowa. Lead mining drove the county’s
early economy, followed by boat building, meatpacking and manufacturing. The 1980s farm crisis hit
the county hard, pushing unemployment to 23 percent in one month of 1982, before diversification
into health care, education and light manufacturing rebuilt the economy through the 1990s.

Getting There

No interstate highway crosses Dubuque County. US 20, US 52, US 61 and US 151 all pass through
the county, along with Iowa Highway 3, and US 20 crosses the Mississippi into Illinois on the
Julien Dubuque Bridge.

• Dyersville — about 25 miles west of Dubuque
• Cascade — about 25 miles southwest of Dubuque
• Epworth — about 12 miles west of Dubuque
• Galena, Illinois — about 15 miles southeast of Dubuque

Dubuque Regional Airport, eight miles south of the city on US 61, handles general aviation
only after its last scheduled airline service ended in January 2026; the nearest airport with
commercial flights is the Eastern Iowa Airport, serving Cedar Rapids and Iowa City to the
southwest. The
county has no Amtrak service — passenger rail last ran through Dubuque in 1981, and today
Canadian National and Canadian Pacific freight trains are the only rail traffic through the
county.

Frequently Asked Questions

Where is Dubuque County located?
It sits in northeastern Iowa on the Mississippi River, bordered by Clayton, Jackson, Jones and
Delaware counties in Iowa plus Grant County, Wisconsin and Jo Daviess County, Illinois across the
river.

What is the population of Dubuque County?
99,266 at the 2020 census, with a 2025 estimate near 99,381.

How big is Dubuque County?
616.46 square miles (1,596.6 km2), of which 608.30 square miles are land.

What is the county seat of Dubuque County?
Dubuque, founded in 1788 and the oldest city in Iowa, is the county seat and largest city.

How many towns and cities are in Dubuque County?
Twenty-one incorporated cities, from Dubuque and Asbury down to Durango and Bankston, plus 12
unincorporated communities including Center Grove and Washington Mills.

What ZIP codes does Dubuque County use?
52001 through 52004 and 52099 for Dubuque, plus separate codes for each of the county’s
other cities including 52002 for Asbury and 52040 for Dyersville.

What is Dubuque County known for?
Julien Dubuque, the first documented European settler in Iowa, and Dyersville’s Field of
Dreams movie site and National Farm Toy Museum.

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