The diverse habitats of Hamilton-Trenton Marsh abut the Delaware River and are bordered on three sides by urban development. This site is a matrix of upland habitats, including deciduous woodland and scrub-shrub, and wetland habitats, including tidal and nontidal wetlands as well as the open waters of the Delaware River, Crosswicks Creek, Watson's Creek and Spring Lake. It also links the Crosswicks, Delaware & Raritan and Delaware River greenways. This site contains the Trenton Marsh Natural Heritage Priority Site. Designated by New Jersey Department of Environmental Protection (NJDEP), Natural Heritage Priority Sites are considered the state?s most significant natural areas.

Ornithological Summary

Conservation Concern ? State-endangered: Pied-billed Grebe (B)

Conservation Concern ? State-endangered: Bald Eagle (B)

Conservation Concern ? State-special Concern: Cliff Swallow (B)

Regional Responsibility Species - BCR 30 Forested Wetland: Wood Duck, Mallard, Fish Crow (B)

Significant Congregations of Waterfowl (SM)

Significant Congregations-Exceptional Diversity

Significant Migrant Stopover/Flyover-Landbirds (SM, FM)

Conservation Issues

Nonnative flora, including the common reed (Phragmites australis) and mile-a-minute vine (Persicaria perfoliatum), outcompete native vegetation and reduce habitat diversity. Pollution problems include effluent from the Hamilton Township sewage treatment plant and a coal-fired power plant at the lower end of Duck Island. Recreational overuse includes off-road vehicles and unauthorized digging for archaeological artifacts. Although portions of the Hamilton-Trenton Marsh are protected as state, county and municipally-owned park land, residential and commercial development threaten the site?s remaining unprotected habitats. Delaware & Raritan Greenway Land Trust (D&R Greenway), a land conservancy, is a leading organization in land protection efforts at the Marsh and oversees implementation of the Hamilton-Trenton Marsh Management Plan. Friends for the Hamilton-Trenton-Bordentown Marsh and the Science and Education Committee, formed by D&R Greenway, advocate for protection of the site.


Owned by: Mercer County
Contact: Donna Lewis
McDade Administration Building
640 South Broad Street
Trenton, NJ


Deciduous forest, tidal and nontidal wetlands

Stay abreast of Audubon

Our email newsletter shares the latest programs and initiatives.