Jefferson County, Indiana

Jefferson County is a county in Indiana, United States, on the Ohio River in the state’s
southeastern corner, about 48 miles northeast of Louisville. It had a population of 33,147 at the
2020 census, an estimated 33,279 by 2025, and covers 362.89 square miles (939.9 km2) centred near
38°47′N 85°26′W.

Madison is the county seat and the county’s only city; its postal code is 47250. The county
holds 1 city, 3 incorporated towns and 25 unincorporated communities — including three census
designated places — spread across 10 townships, and it runs on Eastern Time. Its FIPS code is
18077.

Towns & Villages in Jefferson County

Jefferson County has 29 named places on record: 1 city, 3 incorporated towns, 3 census designated
places (Canaan, Deputy and Kent, which carry their own 2020 population counts) and 22 informal
unincorporated communities with no government or CDP status of their own.

Four names on the site’s old list could not be traced to any township, gazetteer or Census
record for Jefferson County — Central, Five Points, Midway and Wakefield — and are dropped
here rather than guessed at. Marble Hill and Antioch Grange are historical sites, not active
settlements: Marble Hill was the site of a nuclear power plant abandoned mid-construction in 1984,
and Antioch Grange is listed as an extinct town in Hanover Township. Kent, Indiana is a
disambiguation page covering both this CDP and the unrelated town of Kentland in Newton County
— the two are not the same place.

ZIP Codes

• 47250 — Madison (also serves Brooksburg, Canaan and Kent, none of which has a ZIP of its own)
• 47243 — Hanover
• 47231 — Dupont
• 47230 — Deputy

The remaining unincorporated communities — North Madison, Wirt, Ringwald, Wirt Station,
Swanville, Lancaster, Middlefork, Chelsea, Paynesville, Saluda, Marble Hill, Parkers Station,
Belleview, Bryantsburg, Barbersville, China, Neavill Grove, Smyrna, Volga, Hanover Beach and
Manville — have no ZIP code of their own; mail is delivered under the nearest post town’s
code.

Geography

Jefferson County sits on bluffs above the Ohio River in Indiana’s hill country, where the
river valley cuts a deep canyon through the surrounding uplands. Of the county’s 362.89 square
miles, 360.63 are land and 2.26 are water, about 0.62 percent. Clifty Falls State Park, on
Madison’s west side, encloses the canyon of Big Clifty Creek and several waterfalls, with high
ground rising roughly 400 feet above the river.

Ripley County lies to the north, Switzerland County to the east, Jennings County to the
northwest, Scott County to the west, and Clark County to the southwest. Carroll County and Trimble
County, both in Kentucky, lie across the Ohio River to the south. Ripley County, Switzerland County, Jennings County, Scott County and Clark County all border Jefferson
directly on the Indiana side.

Demographics

Jefferson County had a population of 33,147 at the 2020 census, and the latest estimate puts the
county near 33,279 residents. Madison and Hanover are by far the two largest communities, together
holding roughly half the county’s population. Median household income runs $64,577 (2024
estimate), below Indiana’s statewide figure of $69,477 (2023 ACS). Population density works out
to about 92 people per square mile of land.

Economy & Local Life

Manufacturing employs the most workers in the county, about 3,481 people, followed by health
care and social assistance at 2,127 and retail trade at 1,818. Hanover College, founded in 1827 and
Indiana’s oldest private college, enrolls about 1,070 undergraduates on its campus above the
Ohio River near Hanover. King’s Daughters’ Health operates the county’s hospital in
Madison. The county’s biggest annual event is the Madison Regatta, an unlimited hydroplane race
held over the July 4 weekend that draws 70,000 to 100,000 visitors — Madison co-owns Miss
Madison, the only community-owned unlimited hydroplane in the world.

History

Indiana’s territorial legislature formed Jefferson County on February 1, 1811, out of Dearborn
and Clark Counties. It was named for Thomas Jefferson, the Northwest Ordinance’s chief
draftsman and U.S. president from 1801 to 1809. Madison was platted in 1810 and its first lots sold
in 1811.

Madison’s position across the Ohio River from Kentucky, then a slave state, made it an
important stop on the Underground Railroad before the Civil War. Its downtown, 133 blocks known as
the Madison Historic Landmark District, received National Historic Landmark designation in 2006.
The 1974 Super Outbreak spawned an F4 tornado that destroyed about 300 homes in Madison and killed
seven residents. Construction began on the Marble Hill Nuclear Power Plant in Saluda Township near
Hanover in 1977; Public Service Company of Indiana abandoned the half-finished plant in 1984 at a
loss of $2.5 billion, and the site has been under demolition since 2005.

Getting There

No interstate highway crosses Jefferson County. U.S. Route 421 runs through Madison, along with
State Roads 3, 7, 56, 62, 250, 256, 356 and 362.

• Louisville, Kentucky — about 48 miles southwest
• Cincinnati, Ohio — about 68 miles northeast

Jefferson County has no scheduled airline or passenger-rail service of its own; residents fly out
of Louisville Muhammad Ali International Airport or Cincinnati/Northern Kentucky International
Airport, roughly the same distances as the cities above.

Frequently Asked Questions

Where is Jefferson County located?
It sits on the Ohio River in Indiana’s southeastern corner, about 48 miles northeast of
Louisville, bordered by Ripley, Switzerland, Jennings, Scott and Clark counties.

What is the population of Jefferson County?
33,147 at the 2020 census, with an estimate near 33,279 by 2025.

How big is Jefferson County?
362.89 square miles (939.9 km2), of which 360.63 square miles are land.

What is the county seat of Jefferson County?
Madison, platted in 1810, is the county seat and its only city.

How many towns and villages are in Jefferson County?
Madison plus three incorporated towns — Hanover, Dupont and Brooksburg — three census
designated places (Canaan, Deputy and Kent), and 22 smaller unincorporated communities.

What ZIP codes does Jefferson County use?
47250 for Madison, Brooksburg, Canaan and Kent; 47243 for Hanover; 47231 for Dupont; and 47230 for
Deputy.

What is Jefferson County known for?
Madison’s Ohio River Historic Landmark District, the Madison Regatta hydroplane races each
July, Hanover College, and the abandoned Marble Hill Nuclear Power Plant.

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