Blair County, Pennsylvania

Blair County is a county in Pennsylvania, United States, in the Allegheny Mountains of
south-central Pennsylvania, roughly midway between Pittsburgh and Harrisburg along US 22. It had
a population of 122,822 at the 2020 census, an estimated 119,541 by 2025, and covers 526 square
miles (1,360 km2) centred near 40°28′N 78°21′W.

Hollidaysburg is the county seat; its postal code is 16648. The county holds 1 city, 9
incorporated boroughs and 15 townships, plus dozens of smaller unincorporated communities, and it
runs on Eastern Time.

Towns & Villages in Blair County

Blair County has one city and nine boroughs on record, all independent municipalities that sit
outside any township. CDP stands for census designated place; Unincorp. covers crossroads and rural
communities with no formal boundary.

The county’s gazetteer also names more than 80 smaller unincorporated communities and
crossroads — hamlets too small to carry their own Census population count. The table below
lists 25 of the more commonly cited ones; the rest are marks on the map rather than population
centers.

Frankstown, the unincorporated village that gave Frankstown Township its name, sits inside the
township of the same name rather than being confused with it. Tyrone borough and Tyrone Township
are two separate municipalities that do not overlap — the borough incorporated out of the
township in 1857 and the two have run independently since.

Townships

Blair County’s 15 townships ring the county’s boroughs and its one city; none of them contains
Altoona, which sits outside any township as an independent city.

ZIP Codes

• 16601–16603 — Altoona
• 16648 — Hollidaysburg
• 16686 — Tyrone
• 16673 — Roaring Spring
• 16662 — Martinsburg
• 16617 — Bellwood
• 16635 — Duncansville
• 16693 — Williamsburg
• 16641 — Tunnelhill
• 16665 — Newry

Most of the county’s unincorporated communities carry no ZIP of their own; mail there is
delivered under whichever incorporated town’s post office serves the route, most often Altoona,
Hollidaysburg or Tyrone.

Geography

Blair County sits in the Allegheny Mountains, part of the Appalachian ridge-and-valley belt that
runs through south-central Pennsylvania. Of its 527 square miles, 526 are land and 1.3 are water,
about 0.2 percent — the county has no large natural lake. The Frankstown Branch of the
Juniata River forms at the village of Claysburg, where Beaverdam Creek meets South Poplar Run, and
flows north through the county before turning east toward the main Juniata River. Altoona sits at
the base of the Allegheny Front, the steep escarpment that the Pennsylvania Railroad’s Horseshoe
Curve was built to climb.

Centre County and Clearfield County lie to the north, Huntingdon County to the east, Bedford
County to the south, and Cambria County to the west. Centre County, Clearfield County, Huntingdon County and Cambria County all border Blair directly;
Bedford County has no live page on this site to link.

Demographics

Blair County had a population of 122,822 at the 2020 census, and the latest estimate puts the
county near 119,541 residents by 2025, a decline typical of the region’s older industrial
counties. Altoona and Hollidaysburg are the county’s two largest communities. Median household
income in the county runs about $62,382 (2024, Census/Data USA estimate), well below
Pennsylvania’s statewide figure of $73,824 (2023 ACS). Population density works out to roughly 233
people per square mile of land.

Economy & Local Life

Health care and social assistance is the county’s largest employment sector, with about 10,238
workers, followed by retail trade at 7,646 and manufacturing at 6,144. UPMC Altoona, the region’s
main hospital system, anchors much of that health care employment. Sheetz, the convenience-store
chain, is headquartered in Altoona and remains one of the county’s largest private employers.
Boyer Candy Company, maker of Mallo Cups, also operates from Altoona, a holdover from the city’s
manufacturing base. Altoona grew up as a Pennsylvania Railroad shop town starting in 1849, and the
Railroaders Memorial Museum preserves that history downtown, alongside the former Juniata Shops
complex.

History

Pennsylvania’s legislature created Blair County on 26 February 1846, carving it out of
Huntingdon and Bedford counties. Hollidaysburg became the county seat.

The county’s defining engineering feat is the Horseshoe Curve, a sweeping bend in the
Pennsylvania Railroad’s main line built between 1851 and 1854 to let trains climb the Allegheny
Front west of Altoona, replacing the older Allegheny Portage Railroad. It opened on 15 February
1854 and was named a National Historic Landmark on 13 November 1966. During the Second World War
the curve was a listed target of Operation Pastorius, a German Abwehr sabotage plot: four agents
landed by U-boat on Long Island in June 1942 with orders to destroy the Curve along with the Hell
Gate Bridge, but the plot collapsed after one of the saboteurs, George John Dasch, turned himself
in to the FBI before any attack was carried out.

Getting There

Interstate 99 and US Route 220 run the length of the county on a north–south line, and US
Route 22 crosses it east–west, connecting toward Pittsburgh to the west and Harrisburg to the
east. Pennsylvania Routes 36, 164, 350, 453, 550, 764, 865, 866 and 867 fill in the local network.

• Altoona — the county’s own largest city, on I-99/US 220
• Hollidaysburg — the county seat, just south of Altoona on US 22
• Tyrone — the county’s northern anchor town, on I-99/US 220
• Johnstown — the nearest larger city outside the county, southwest via US 22

Altoona-Blair County Airport handles general aviation; there is no scheduled commercial
airline service based in the county. Amtrak’s Pennsylvanian train stops at Altoona’s station on
its daily run between New York and Pittsburgh.

Frequently Asked Questions

Where is Blair County located?
It sits in the Allegheny Mountains of south-central Pennsylvania, roughly midway between
Pittsburgh and Harrisburg along US 22, bordered by Centre, Clearfield, Huntingdon, Bedford and
Cambria counties.

What is the population of Blair County?
122,822 at the 2020 census, with a 2025 estimate near 119,541.

How big is Blair County?
526 square miles (1,360 km2) of land, plus 1.3 square miles of water, for a total of 527 square
miles.

What is the county seat of Blair County?
Hollidaysburg, created with the county in 1846, is the county seat.

How many towns and cities are in Blair County?
One city, Altoona, and nine boroughs — Hollidaysburg, Tyrone, Roaring Spring, Martinsburg,
Bellwood, Duncansville, Williamsburg, Tunnelhill and Newry — plus 15 townships and more than
80 smaller unincorporated communities.

What ZIP codes does Blair County use?
16601 through 16603 for Altoona, 16648 for Hollidaysburg, 16686 for Tyrone, and separate codes for
each of the county’s smaller boroughs.

What is Blair County known for?
The Horseshoe Curve, a National Historic Landmark rail curve near Altoona that was a listed
sabotage target in the 1942 Operation Pastorius plot, and Sheetz, the convenience-store chain
headquartered in Altoona.

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