The Trust's Gravel Hill Preserve is so named for the composite gravel sized rocks forming an elevated area overlooking the Delaware River. The New Jersey Green Acres Program and the Trust recently preserved 82 acres, known as the Silva Farm, as an addition to the Trust's Gravel Hill Preserve. The open fields of the preserve provide hay for farmers and are cut to benefit grassland birds such as bobolink, American kestrel, and eastern meadowlark. The hardwood forest provides an important buffer around areas of the preserve where habitat for wild comfrey, black cohosh and many other native herbs and wildflowers are found. In the days when every home was heated by a cook stove, the forested mountain top at Gravel Hill was divided into small woodlot parcels where owners from town could have their own private source for firewood. Today, Gravel Hill Preserve includes a maze of the old logging roads which can be used for hiking. Bluffs, extending out to the Delaware River, offer beautiful views over the river.
A narrow lane leading from Spring Garden Road, leads to small parking area. From here birders get easy access to the grasslands. No hunting is permitted at this preserve at this time.