THE SUFFOLK COUNTY LAND BRIEF
Land in the
Cape Cod/Long Island setting.
Suffolk County has 910.9 square miles of land in New York. 3 mapped landscape regions meet across Suffolk County: Cape Cod/Long Island, Long Island Sound Coastal Lowland, Barrier Islands/Coastal Marshes.
Sandy coastal landscapes combine beaches, dunes, bays and marshes with oak-pine woodland. These pine-barrens settings form a transition between warmer southern coasts and rockier shores farther north.
Regional context: Atlantic Coastal Pine Barrens ↗ · Regional mapping across the county footprint
Where the landscape changes
Suffolk County intersects 3 mapped regional units. The largest mapped shares are:
- Cape Cod/Long Island70.5%
- Long Island Sound Coastal Lowland16.7%
- Barrier Islands/Coastal Marshes12.7%
Northeastern Coastal Zone in Suffolk County
Irregular plains and low hills form a coastal transition with glacial lakes and oak-pine woodland. This northeastern landscape is gentler than the mountainous country farther inland.
Read the regional source ↗Finding your parcel within Suffolk County
The atlas lists 169 cities, towns, townships, and Census communities associated with Suffolk County, including Brookhaven, Southampton, Islip. The list includes overlapping geography types and does not divide the county into exclusive service areas.
Suffolk County by land and water
The Census records 1,462.3 square miles of water within Suffolk County, or 61.6% of its total area. That share is close to Suffolk County’s 61.6%. This is geographic context; waterfront status and usable land must be checked at the parcel.
For scale, Suffolk County has 60.4 times the land area of nearby Riverhead CDP (15.1 square miles). These areas describe boundaries, not comparable property prices.
The Census boundary meets Nassau County within New York. A tract near one of these lines should be matched to the county identifier on its own records.

