Location: Tredyffrin   •   Acreage: 66.6 acres  

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Click For Trail Map

natural characteristics

  • 66.6 acres on Diamond Rock Hill, marking the northern border of the Great Valley

  • 110 foot oaks, mountain laurel, rock formations, steep slopes, abutting old quarry


Take Yellow Springs Road, then north on Howell Road and turn right on Chautauqua Trail. Walk along Horse-shoe Trail to Preserve entrance.

(Click on red marker to open Google Maps for directions from your location)


Preserve History

Diamond Rock Preserve is a 66-acre preserve located on the South facing slope of Diamond Rock Hill which is part of North Valley Hill. The Preserve is bordered by residential development on the north, east, and west sides and the Pennsylvania Turnpike to the south. It is a wooded area made up of steep slopes and a quartzite ridge running east and west along the top.

The land was originally associated with the “Welsh Tract” granted by William Penn. By 1686 the original 40,000-acre grant had been expanded to include what is now Tredyffrin Township and this preserve. By late 1800 the land on the mountain had been sub-divided and combined with farm properties in the valley, below Yellow Springs Road. The hillside forest was used as a source of lumber for these farms. By 1950 the Pennsylvania Turnpike was constructed between the mountain and the valley which led to a redevelopment of the land and an end to any significant lumber use.

Diamond Rock Preserve was created by five separate acquisitions. The first in 1994, when Natural Lands Trust donated 24 acres to Open Land Conservancy. In 1998, 5.35 acres were obtained from the developers of the Chautauqua subdivision and in 1999 OLC was given an additional 1.36 acres as a gift from the High Mountain development. The Preserve was expanded significantly in 2008 with the purchase of an additional 20.6 acres on its western border. This purchase was funded by grants from Chester County’s Preservation Partnership Program and Pennsylvania’s Community Conservation Partnerships Program. In 2011 the Conservancy completed an agreement to purchase an additional 15 acres extending the preserve further along the Turnpike to the west. This acquisition was funded similarly to the 2008 acquisition.

The entire 66-acre preserve is comprised of woodland, primarily made up of oak, tulip and beech trees with an understory of mountain laurel, cherry birch and maple leaf viburnum. If you have been to the Pocono Mountains, the preserve will remind you very much of that area.

The preserve is also home to a range of animal life typically found in close proximity to suburban areas. Various mammals inhabit the preserve; the most significant being the white tailed deer. The Valley Forge Chapter of the Audubon Society conducted bird counts on four separate occasions and observed at least 32 separate species, including various types of warblers, eastern bluebirds and also a pileated woodpecker.

Access to the preserve is provided by a 1340-foot section of the Horseshoe Trail that runs off of a private driveway on Chautauqua Circle. The Horseshoe Trail was opened to the public in 1935 for equestrian and pedestrian use and continues to pass through what is now preserve land. While Diamond Rock Preserve is the least visited of OLC’s preserves, it is often used by neighbors of the Preserve.

The Conservancy is gradually building and marking a trail network in the preserve, thanks in particular to our student volunteers and interns. Members who are ready for a strenuous hike down from the ridge and back amongst the majestic old trees can also play a part in establishing the trails. We encourage members to visit the preserve this Fall to enjoy the changing colors.