Wood’s Chrome Mine, the State Line district

There is no single gate here. The chromite district runs 60 square miles across two states and six separately owned tracts, so who you ask depends on where you stand.

The State Line Serpentine Barrens run for 60 square miles along the Pennsylvania and Maryland border, and they hold some of the last major remnants of serpentine grassland in eastern North America. The thin soils over that pale green bedrock carry high levels of nickel, chromium and other metals that most plants and animals cannot tolerate. What survives instead is a set of unusual, rare and endangered species that adapted to the harsh chemistry over thousands of years.

The chromium in the ground is also why there are mines here. Through the 19th century the Pennsylvania and Maryland serpentine barrens were worked for chromite and magnesite. Pennsylvania has named the site an Outstanding Geologic Feature, and this pin sits inside that mining district.

Before you plan a collecting trip, work out who owns what. The protected area is not one park but an assemblage of six tracts held by the Nature Conservancy, the State of Pennsylvania, two counties, a township and private owners. The largest is Nottingham County Park in Chester County, itself a National Natural Landmark. Goat Hill Serpentine Barrens is next, owned jointly by the Conservancy and the Pennsylvania Forestry Department as a unit of William Penn State Forest. Chrome Serpentine Barrens is shared by Elk Township and the Conservancy, and Rock Springs Preserve in Lancaster County is managed by the Lancaster Conservancy. The Conservancy lists access as limited, with different hours and requirements at every site. Ask first.

Reaching the two main trailheads is simple enough. For Goat Hill, take US Route 1 south about 2.5 miles past the Maryland line and turn right onto Red Pump Road, and the well-marked parking lot is on the left at the powerline. For Chrome, leave Route 1 at the Oxford exit onto Route 10, drive 1.7 miles into the centre of Oxford, turn left on Market Street, cross the railroad tracks, turn right on Fifth Street for 2.7 miles, then cross Media Road onto Barrens Road for another 0.8 miles.

These barrens survive because people fought for them. The Conservancy has been protecting serpentine here since 1979, when it joined the Concerned Citizens of West Nottingham Township to oppose a plan to quarry the serpentine rock outright. They blocked it.