THE SULLIVAN COUNTY LAND BRIEF
Land in the
Low Poconos setting.
Sullivan County has 968.1 square miles of land in New York. 7 mapped landscape regions meet across Sullivan County: Low Poconos, Delaware-Neversink Highlands, Catskills Transition, 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 7 mapped regional units. The largest mapped shares are:
- Low Poconos38.3%
- Delaware-Neversink Highlands29.7%
- Catskills Transition19.8%
- Catskill High Peaks7.9%
- Northern Glaciated Ridges2.3%
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 ↗Northeastern Highlands in Sullivan County
Forested hills and mountains span northern New England, the Adirondacks and higher Catskills. Glacial lakes and steep streams accompany a transition between northern hardwood and spruce-fir forests.
Read the regional source ↗Finding your parcel within Sullivan County
The atlas lists 46 cities, towns, townships, and Census communities associated with Sullivan County, including Mamakating, Rockland, Bethel. 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 28.5 square miles of water within Sullivan County, or 2.9% of its total area. That share is close to Sullivan County’s 2.9%. This is geographic context; waterfront status and usable land must be checked at the parcel.
For scale, Sullivan County has 193 times the land area of nearby Mongaup Valley CDP (5.02 square miles). These areas describe boundaries, not comparable property prices.
The Census boundary meets Delaware County, Orange County, Ulster County within New York. A tract near one of these lines should be matched to the county identifier on its own records.

