Places We Protect

Sussex Swamp Preserve

New Jersey

Barred owl
Barred owl The wetlands of Sussex Swamp contain numerous imperiled species that find refuge in this natural oasis, such as the barred owl. © Shutterstock

Sussex Swamp Preserve spans nearly 300 acres, protecting one of New Jersey’s largest limestone fens.



Why the Conservancy Selected This Site

Much of the land comprising the Sussex Swamp Preserve was once used as farmland. Today, the preserve represents one of New Jersey's best and largest limestone fens, and is home to a healthy population of Schweitzer's buckmoth. The preserve is one of only six sites where this buckmoth is known to exist. By protecting the integrity of the preserve's limestone fens, sinkholes, and the hydrologic processes that maintain them, it will allow for the protection of viable populations of rare elements, plants, lepidoptera, and amphibians.

What the Conservancy Has Done/Is Doing

Several factors threaten the health of the fen and the rare plants and animals that inhabit the preserve. The butterfly and moth populations are most threatened by collection. The sinkhole ponds used by longtail salamanders are affected by runoff from an adjacent development that drains directly into the pond. Collecting by neighborhood children may also prove a threat for the salamander. The surrounding deciduous forest matrix is greatly threatened by invasive weedy species. Off-road vehicles continue to be a problem at the site.

To preserve the integrity of the Sussex Swamp area, scientists and land stewards constantly monitor the fen and take actions as necessary, to ensure its health is suitable to support native plant and animal inhabitants. Scientists also conduct biological monitoring of the Schweitzer's buckmoth, including counting the larvae and getting a general idea on the health of the population.

The preserve is currently closed to the public.




Andover Township, Sussex County, NJ

Map with marker: This preserve is currently closed to the public.


Nearly 300 acres

Explore our work in this region

Please note: This preserve is currently closed to the public.

Why You Should Visit

Sussex Swamp Preserve spans nearly 300 acres and protects one of New Jersey's best and largest limestone fens. Located about a mile from downtown Newton in Sussex County, the preserve is home to stunning limestone ridges, dense rolling forests, and vital wetlands. This significant wetland community contains numerous globally and state imperiled plant and animal species that find refuge in this natural oasis, including the Schweitzer's buckmoth and the barred owl. The preserve includes a portion of the watershed of Stickle Pond to the southeast, and drains into both the Paulinskill and Pequest Rivers in the Upper Delaware Watershed Management Area.

Visitation guidelines

  • No pets (except service dogs).
  • No camping, fires, or alcoholic beverages.
  • Littering and dumping are prohibited.
  • No collecting, hunting, or trapping.
  • Motorized vehicles, horses, and firearms are prohibited.

What to See


A remarkable diversity of calcium-dependent plants are supported by this habitat, including the state-rare water sedge (Carex aquatilis), northern bog aster (Aster borealis), ebony sedge (Carex eburnean), pale laurel (Kalmia polifolia), and bog rosemary (Andromeda glaucophylla).


The state-threatened barred owl (Strix varia) makes its home in the area. The adjacent uplands harbor several state-rare butterflies, including Schweitzer’s buckmoth (Hemileaca sp. 2) and the imperiled Northern metalmark (Calephelis borealis). Mitchell’s satyr (Neonympha mitchelli) was first discovered in the state at Sussex Swamp in the mid-1960s; however, collecting caused this butterfly to disappear from the state shortly thereafter.

Trails wind through the marsh edges.

Visitor Information

The preserve is open from dawn until dusk; however, no parking facilities currently exist. Please contact Eric Olsen at The Nature Conservancy’s New Jersey chapter office for visitor information at (908) 879-7262 or