- The Wallkill River NWR is a "riverine floodplain refuge". Its bottomlands provide one of the few large areas of high quality waterfowl habitat remaining in Northwest New Jersey.
The refuge encompasses about 9 miles of the Wallkill River, which flows north from Sparta, New Jersey and enters the Rondout River, a tributary of the Hudson River, near Kingston, New York. The Wallkill River floods extensively in the spring, fall, and winter.
The river's broad floodplains are primarily forested wetlands and wet meadows. The rolling topography of the area is found on the refuge as well. Oak-covered limestone ridges parallel the river, sometimes coming right to the river's edge. Wetlands and forests yield to open farmlands and grasslands at the higher elevations.
The refuge supports a diverse number of species, including 19 species listed by New Jersey as threatened or endangered. These include the American bittern, barred owl, bobolink, Cooper's hawk, grasshopper sparrow, great blue heron, northern harrier, savannah sparrow, sedge wren, short-eared owl, upland sandpiper, vesper sparrow, and wood turtle. The bog turtle is found on the refuge. Black bear and bobcat also occur.
A major grassland and wetland complex, habitat is provided for black ducks, wood ducks, green-winged teal and for shorebirds, songbirds and raptors. Waterfowl and shorebirds are common during migration, as are neotropical songbirds. Many species of songbirds also nest on the refuge, including chestnut-sided warblers and scarlet tanagers.
The refuge is located in Sussex County, New Jersey and Orange County, New York.