This site incorporates approximately 750-acres owned by the Verplanck family from the seventeenth century until 1942, when it was donated to the NYS Department of Education to be utilized as a teaching farm by SUNY Farmingdale. The land was transferred to the NYS Department of Environmental Conservation in 1973, and since 2010 the non-profit Stony Kill Foundation has managed the daily operations of the property.
Stony Kill Farm includes land situated on both sides of Route 9G. East of the state highway, there are diverse habitats that include hardwood forests, meadows, wetlands, and ponds. While public roads traverse the site resulting in discrete tracts, the areas are linked by hiking trails.
West of Route 9G, is a working farm, visitor center, and other public amenities. The farmstead, located near the southern edge, includes a cluster of vernacular buildings, livestock paddock, picnic area, community garden, and small-scale demonstration farm. A paved road leads to the northwest, delineating open fields: the sloping pasture to the east, framed by a perimeter fence, is used to graze livestock, while the opposite field is dedicated to crop cultivation. The road leads to a manor house completed in 1843, now serving as a visitor center. A looped drive encloses a teardrop shaped lawn embellished with a perennial garden, a flagpole, and tree specimens, including oak and dawn redwood. Hiking trails proceed north, climbing sloped forested terrain and skirting mowed fields. This section, west of Route 9G, was listed in the National Register of Historic Places in 1980.