THE WESTMORELAND COUNTY LAND BRIEF
Land in the
Pittsburgh Low Plateau setting.
Westmoreland County has 1,027.7 square miles of land in Pennsylvania. 4 mapped landscape regions meet across Westmoreland County: Pittsburgh Low Plateau, Monongahela Transition Zone, Forested Hills and Mountains, among others.
Rounded wooded hills and intervening valleys form an unglaciated plateau landscape. Valley floors contain much of the region's open land, contrasting with its more forested slopes.
Regional context: Western Allegheny Plateau ↗ · Regional mapping across the county footprint
Where the landscape changes
Westmoreland County intersects 4 mapped regional units. The largest mapped shares are:
- Pittsburgh Low Plateau39.3%
- Monongahela Transition Zone28%
- Forested Hills and Mountains20.4%
- Uplands and Valleys of Mixed Land Use12.3%
Central Appalachians in Westmoreland County
A rugged, deeply cut plateau of sandstone, shale and related rocks supports extensive forest. High hills and low mountains distinguish this Appalachian landscape from smoother neighboring regions.
Read the regional source ↗Finding your parcel within Westmoreland County
The atlas lists 86 cities, towns, townships, and Census communities associated with Westmoreland County, including Derry, Ligonier, Hempfield. The list includes overlapping geography types and does not divide the county into exclusive service areas.
Westmoreland County by land and water
The Census records 8.22 square miles of water within Westmoreland County, or 0.8% of its total area. That share is close to Westmoreland County’s 0.8%. This is geographic context; waterfront status and usable land must be checked at the parcel.
For scale, Westmoreland County has 15.2 times the land area of nearby Unity township (67.4 square miles). These areas describe boundaries, not comparable property prices.
The Census boundary meets Allegheny County, Armstrong County, Butler County, Cambria County, Fayette County, Indiana County, Somerset County, Washington County within Pennsylvania. A tract near one of these lines should be matched to the county identifier on its own records.

