While there are playgrounds,golf courses, stables and a museum within the reservation, much of the 1,945 acre (7.8 km²) parcel is forested, and managed for the preservation of its natural resources. The most popular recreational activities in the reservation are hiking and horseback riding on its many trails. The county-owned Watchung Stables are located on a large cleared area in the eastern end of the park, and at the center is the Trailside area, a large park with picnic tables and playground equipment. The Trailside Museum and Nature Center is at the southern edge, along Coles Avenue in Mountainside. Climbers within the state have been drawn to the bouldering opportunities on the cliffs along the brook and Diamond Hill Road at the Watchung's western boundary, although that is not permitted and indeed actively discouraged by the county.
The land in the reservation has never been pristine and undeveloped either before or after the reservation's establishment. An entire village, Feltville, once existed in the woods in the northwestern quadrant. One popular hike in the western reservation goes through a pine plantation left by the Civilian Conservation Corps in the 1930s.
Twice higher levels of government have taken land in the reservation, over heavy public protest, for their own purposes. The first time was in the late 1950s when the U.S. Army built a Nike missile base and operated it between 1957 and 1963; it is today the site of the stables. A lasting effect on the reservation came in the 1980s when, following years of litigation and public activism, the New Jersey Department of Transportation got approval for the completion of Interstate 78 through the northern fringe of the reservation. Land bridges were built to allow wildlife to travel between both parts of the Watchung unmolested, though in the end they were not used by animals.