County Maps US

Blair County, Pennsylvania

A county in Pennsylvania, ranked 28 of 67 by population.

CountyFIPS 42013

Within Pennsylvania
Blair County, highlighted, with the areas around it. Boundaries generalised from the 2025 Census cartographic boundary file; neighbour fills carry no data. The dot marks Hollidaysburg, the county seat, located via the 2025 Census Gazetteer.

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Population
119,541
-3,126 (-2.5%) since 2020
Land area
525.1
square miles. A further 0.2% of the total area is water
Population density
228
people per square mile, computed rather than published
County seat
Hollidaysburg
Seat of county government.
Established
1846
179 years ago
Largest city
Altoona city
Population 42,347.

Sources: US Census Bureau, Population Estimates Program, Vintage 2025 Population Estimates, released 26 March 2026; US Census Bureau, Gazetteer Files, 2025 Gazetteer Files, released 10 September 2025; Wikidata (CC0), Wikidata. Retrieved 30 August 2026.

Satellite view

Aerial imagery of Blair County with its boundary drawn on top. A map shows you the shape; this shows you what is inside it, and which side of the line a place falls on.

Aerial view of Blair County, Pennsylvania from the USGS National Map, with its boundary outlined
Imagery: USGS National Map, USGS Imagery Only, public domain, requested from USGS by your browser when you reach this point on the page, at 630 by 800 pixels. The boundary is the 2025 Census cartographic boundary file, reprojected to Web Mercator to match the imagery. You can also open the USGS National Map viewer.

Where Blair County ranks

Position among the 67 counties of Pennsylvania, and among all 3,144 US counties and county-equivalents. Computed from the figures on this page.

MeasureValueIn PennsylvaniaNationally
Population119,54128th of 67541st of 3,144
Land area525.1 sq mi43rd of 671,993rd of 3,144
Population density228 per sq mi24th of 67526th of 3,144
Median household income$62,38248th of 671,858th of 3,143

Full data for Blair County

Every figure below is attributed to the Census Bureau product it came from, with the vintage of that product.
MeasureValueSource and vintage
Population119,541Vintage 2025 Population Estimates
Population in 2020122,667Vintage 2025 Population Estimates
2020 estimates base?122,824Vintage 2025 Population Estimates
Land area525.1 sq mi2025 Gazetteer Files
Water area1.3 sq mi2025 Gazetteer Files
Total area526.3 sq mi2025 Gazetteer Files
Population density?228 per sq miComputed: Vintage 2025 estimates divided by 2025 Gazetteer land area
Median household income$62,382American Community Survey 2020-2024 5-Year Estimates
Median home value$161,100American Community Survey 2020-2024 5-Year Estimates
Median age43.1American Community Survey 2020-2024 5-Year Estimates
Households50,558American Community Survey 2020-2024 5-Year Estimates
Housing units55,901American Community Survey 2020-2024 5-Year Estimates

Sources: US Census Bureau, Population Estimates Program, Vintage 2025 Population Estimates, released 26 March 2026; US Census Bureau, Gazetteer Files, 2025 Gazetteer Files, released 10 September 2025; US Census Bureau, American Community Survey, American Community Survey 2020-2024 5-Year Estimates, released 29 January 2026. Population density is computed here, not published: it divides the Vintage 2025 population estimate by the 2025 Gazetteer land area, which are two different Census products. Retrieved 30 August 2026.

How the population changed

The Census Bureau publishes the components behind an estimate, not just the total. For the year to July 2025:

Births minus deaths
-490
1,120 births, 1,610 deaths
Net migration
-25
More people moved out than moved in.

Source: US Census Bureau, Population Estimates Program, Vintage 2025 Population Estimates, released 26 March 2026. Retrieved 30 August 2026.

The 5 areas bordering Blair County

Ordered by the length of the border actually shared, which the Census Bureau publishes in its county adjacency file and which no other county reference presents.

Bordering areaStateShared borderPopulation
Huntingdon CountyPennsylvania48 mi43,001
Cambria CountyPennsylvania34 mi128,968
Bedford CountyPennsylvania28 mi47,480
Centre CountyPennsylvania13 mi157,393
Clearfield CountyPennsylvania0.9 mi78,100

Source: US Census Bureau, County Adjacency File, 2025 County Adjacency File, released 15 September 2025. Retrieved 30 August 2026.

All 67 counties of Pennsylvania

Open the interactive Pennsylvania county map, or jump straight to any of them.

Data on this page last rebuilt 30 August 2026. How these figures are produced.