Dauphin County, Pennsylvania

Dauphin County is a county in Pennsylvania, United States, centred on Harrisburg, the state
capital, about 100 miles west of Philadelphia. It had a population of 286,401 at the 2020
census, an estimated 289,593 by 2024, and covers 558 square miles (1,445 km2) centred near
40°25′N 76°47′W.

Harrisburg is the county seat and Pennsylvania’s capital city; its postal code is 17101. The
county holds 1 city, 16 boroughs and 23 townships, plus 15 census-designated places with no
local government of their own, and it runs on Eastern Time. Its FIPS code is 42043.

Towns & Villages in Dauphin County

Dauphin County has 32 named places on the U.S. Census Bureau’s roll: 1 city, 16 incorporated
boroughs, and 15 census-designated places (CDPs) that have no local government of their own.
Twenty-three townships cover the rest of the land in between; they are listed separately below,
since in Pennsylvania a township is itself a unit of local government, not a rural leftover.

Fifteen more places are census-designated — recognized for Census Bureau counting purposes
but with no borough or township government of their own. Each sits inside one of the county’s
townships, named in the Township column below.

Townships

All 23 townships hold local government of their own, elect their own supervisors or
commissioners, and levy their own taxes — they are not rural gaps between the boroughs.
Lower Paxton is the county’s single most populous municipality of any kind, ahead of Harrisburg
itself.

ZIP Codes

• 17101 — Harrisburg (downtown and the Capitol Complex; also covers the PO-Box-only codes
  17105, 17106 and 17108 used by state agencies)
• 17102–17113 — Harrisburg’s other city ZIPs, which also cover Penbrook (17103),
  Paxtang (17111) and Steelton (17113), none of which has a separate code of its own
• 17033 — Hershey (also serves Palmdale and most of Derry Township)
• 17057 — Middletown (also serves Royalton)
• 17036 — Hummelstown
• 17034 — Highspire
• 17061 — Millersburg
• 17023 — Elizabethville
• 17030 — Gratz
• 17048 — Lykens
• 17032 — Halifax
• 17018 — Dauphin
• 17098 — Williamstown
• 17028 — Grantville (an unincorporated village in East Hanover Township)
• 17097 — Wiconisco (a PO-Box-only code covering the CDP and Wiconisco Township)
• 17005 — Berrysburg (PO Box only)
• 17080 — Pillow (PO Box only)

Colonial Park, Progress, Linglestown, Rutherford, Paxtonia, Lawnton, Skyline View, Bressler,
Enhaut, Oberlin, Lenkerville and Union Deposit have no ZIP code of their own; mail there is
delivered under the nearest incorporated town’s code or Harrisburg’s.

Geography

Dauphin County sits astride Pennsylvania’s Ridge and Valley Appalachians, where Blue
Mountain, Peters Mountain, Stony Mountain and Second Mountain run in parallel ridges across the
county’s northern half. Of its 558 square miles, 525 are land and 33 are water, about 5.9
percent — almost all of it the Susquehanna River, which forms the county’s western
border and splits Harrisburg from West Shore communities in Cumberland County. Swatara Creek,
Wiconisco Creek and Mahantango Creek are the county’s main tributary streams.

Schuylkill County lies to the northeast, Lebanon County to the east, Lancaster County to the
southeast, York County to the south, Cumberland County to the southwest across the Susquehanna,
and Perry County to the west, also across the river. Northumberland County borders the county’s
northern tip but has no page on this site yet. Schuylkill County, Lebanon County, Lancaster County, York County, Cumberland County and Perry County all border
Dauphin directly.

Demographics

Dauphin County had a population of 286,401 at the 2020 census, and the latest estimate puts
the county near 289,593 residents as of 2024. Lower Paxton Township is the county’s single
most populous municipality at 53,514, ahead of Harrisburg’s 50,070 and Swatara Township’s
27,827. Median household income runs $72,737 (2024 ACS 1-year), a touch below Pennsylvania’s
statewide figure of $73,824 (2023 ACS). Population density works out to about 546 people per
square mile of land, concentrated heavily around Harrisburg and thinning out fast toward the
mountain townships in the north.

Economy & Local Life

Health care and social assistance employs the most workers in the county, about 25,542 people,
followed by retail trade at 15,757 and educational services at 11,602. Pennsylvania’s state
government is the region’s single largest employment block, since Harrisburg has been the
capital since 1812 and the Capitol Complex fills much of the city’s core with executive-branch
and legislative offices. Penn State Health Milton S. Hershey Medical Center, in Derry Township, and
UPMC Pinnacle’s Harrisburg-area hospitals are the county’s biggest health care employers. The
Hershey Company, founded by Milton Hershey in Derry Township in 1894, still runs its
world-headquarters and a working chocolate plant there, alongside the Hersheypark amusement park
and Hershey’s Chocolate World visitor center. The county’s biggest annual event is Kipona, a
Labor Day weekend riverfront festival on Harrisburg’s City Island and along the Susquehanna,
running since the early 1900s with live music, a Native American cultural festival and a Sunday
fireworks and drone show.

History

Pennsylvania’s legislature formed Dauphin County on March 4, 1785, carving it out of
Lancaster County. It was named for Louis Joseph, Dauphin of France, the eldest son of King Louis
XVI. Harrisburg, built around John Harris Jr.’s trading post on the Susquehanna, became
Pennsylvania’s capital in 1812, moved from Lancaster for its more central location.

On March 28, 1979, Unit 2 of the Three Mile Island Nuclear Generating Station, on an island in
the Susquehanna in Londonderry Township, suffered a partial core meltdown — the most
serious accident in U.S. commercial nuclear power history. No deaths were directly attributed to
the release, but the accident reshaped nuclear plant regulation nationwide. The undamaged Unit 1
reactor kept running for four more decades before the plant shut down for good in 2019.

Getting There

Interstates 81, 83 and 76 (the Pennsylvania Turnpike) all cross the county, converging near
Harrisburg. US 22/322 and US 15 also run through, along with a dense web of state routes serving
the rural townships to the north.

• Lancaster — about 36 miles southeast
• York — about 25 miles south
• Carlisle — about 18 miles west
• Reading — about 54 miles east

Harrisburg International Airport, in Lower Swatara Township within the county itself, is the
nearest commercial airport, with daily flights to major East Coast hubs. Amtrak’s Keystone and
Pennsylvanian trains stop at the Harrisburg Transportation Center downtown, connecting to
Philadelphia, New York and Pittsburgh.

Frequently Asked Questions

Where is Dauphin County located?
It sits in south-central Pennsylvania along the Susquehanna River, bordered by Schuylkill,
Lebanon, Lancaster, York, Cumberland, Perry and Northumberland counties.

What is the population of Dauphin County?
286,401 at the 2020 census, with a 2024 estimate near 289,593.

How big is Dauphin County?
558 square miles (1,445 km2), of which 525 square miles are land and 33 square miles are the
Susquehanna River and its tributaries.

What is the county seat of Dauphin County?
Harrisburg, Pennsylvania’s state capital since 1812, is the county seat.

How many towns and boroughs are in Dauphin County?
One city (Harrisburg) and 16 boroughs, plus 23 townships and 15 unincorporated census-designated
places.

What ZIP codes does Dauphin County use?
17101 through 17113 for Harrisburg and its close-in boroughs, plus separate codes for Hershey
(17033), Middletown (17057), Hummelstown (17036) and the smaller river and mountain towns.

What is Dauphin County known for?
Being home to Pennsylvania’s state government in Harrisburg, The Hershey Company’s chocolate
headquarters in Derry Township, and the 1979 Three Mile Island nuclear accident in Londonderry
Township.

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