THE HUNTERDON COUNTY LAND BRIEF
Land in the
Triassic Lowlands setting.
Hunterdon County has 427.8 square miles of land in New Jersey. 4 mapped landscape regions meet across Hunterdon County: Triassic Lowlands, Reading Prong, Trap Rock and Conglomerate Uplands, among others.
Rounded low hills, open valleys and irregular plains form a transition between Appalachian highlands and the coastal plain. The underlying geology mixes metamorphic, igneous and sedimentary rocks.
Regional context: Northern Piedmont ↗ · Regional mapping across the county footprint
Where the landscape changes
Hunterdon County intersects 4 mapped regional units. The largest mapped shares are:
- Triassic Lowlands72.5%
- Reading Prong21.1%
- Trap Rock and Conglomerate Uplands4.9%
- Northern Limestone/Dolomite Valleys1.4%
Northeastern Highlands in Hunterdon 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 ↗Ridge and Valley in Hunterdon 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 Hunterdon County
The atlas lists 33 cities, towns, townships, and Census communities associated with Hunterdon County, including Readington, Raritan, Delaware. The list includes overlapping geography types and does not divide the county into exclusive service areas.
Hunterdon County by land and water
The Census records 9.56 square miles of water within Hunterdon County, or 2.2% of its total area. That share is close to Hunterdon County’s 2.2%. This is geographic context; waterfront status and usable land must be checked at the parcel.
For scale, Hunterdon County has 18.6 times the land area of nearby Franklin township (23 square miles). These areas describe boundaries, not comparable property prices.
The Census boundary meets Mercer County, Morris County, Somerset County, Warren County within New Jersey. A tract near one of these lines should be matched to the county identifier on its own records.

