THE SULLIVAN COUNTY LAND BRIEF
Land in the
Glaciated High Allegheny Plateau setting.
Sullivan County has 449.9 square miles of land in Pennsylvania. 4 mapped landscape regions meet across Sullivan County: Glaciated High Allegheny Plateau, Glaciated Low Allegheny Plateau, Unglaciated High Allegheny Plateau, among others.
Forest-covered plateau surfaces, high hills and low mountains are underlain by layered sedimentary rocks. Most of this region escaped continental glaciation, leaving deeply cut upland terrain.
Regional context: North Central Appalachians ↗ · Regional mapping across the county footprint
Where the landscape changes
Sullivan County intersects 4 mapped regional units. The largest mapped shares are:
- Glaciated High Allegheny Plateau72.6%
- Glaciated Low Allegheny Plateau22.6%
- Unglaciated High Allegheny Plateau3.4%
- Northern Dissected Ridges and Knobs1.4%
Northern Allegheny Plateau in Sullivan County
Rolling hills, broad valleys and low mountains are mantled by glacial deposits. Sandstone, shale and siltstone underlie a mix of open land and woodland across the northern plateau.
Read the regional source ↗Ridge and Valley in Sullivan County
Long, roughly parallel ridges and valleys follow folded and faulted rock layers. Limestone valleys, sandstone ridges and other geologic contrasts produce varied terrain and numerous regional springs and caves.
Read the regional source ↗Finding your parcel within Sullivan County
The atlas lists 15 cities, towns, townships, and Census communities associated with Sullivan County, including Davidson, Colley, Cherry. The list includes overlapping geography types and does not divide the county into exclusive service areas.
Sullivan County by land and water
The Census records 2.56 square miles of water within Sullivan County, or 0.6% of its total area. That share is close to Sullivan County’s 0.6%. This is geographic context; waterfront status and usable land must be checked at the parcel.
For scale, Sullivan County has 421.3 times the land area of nearby Laporte borough (1.07 square miles). These areas describe boundaries, not comparable property prices.
The Census boundary meets Bradford County, Columbia County, Luzerne County, Lycoming County, Wyoming County within Pennsylvania. A tract near one of these lines should be matched to the county identifier on its own records.

