Potomac Tributaries

South central Pennsylvania is composed of mountains of the Ridge and Valley Province – which is named for the parallel ridges and valleys of the Central Appalachian Mountains – and intermountain tributary watersheds of the Potomac River. This rugged and rural landscape includes the “shale country” and is based on unique geology and soils.

Additional biodiversity significance is found downstream in Maryland, where all of the southward flowing streams and mountain ridges lead. Furthermore, this region is within the watershed of the Chesapeake Bay. Therefore, tributary streams here feed the Potomac River which in turn supplies fresh water to one of the largest estuary ecosystems on earth.

WPC has identified several streams in Bedford and Fulton counties that display significant quality and biodiversity. Sideling Hill Creek, which flows through the southern reaches of Bedford and Fulton counties, is home to important ecosystem features including shale barrens, rare freshwater mussel species and a freshwater sponge.

To the west, Town Creek is another stream system identified as a key target for restoration strategies focused on shale barrens and forest communities. Forests cover a large percentage of the surrounding ridges and portions of the valleys in this landscape. Healthy forests are key to protecting these watersheds.

Fifteen Mile Creek is the third tributary in this region that has been targeted for conservation efforts.

Key Features

  • Medium gradient streams of the Potomac drainage host aquatic species not found elsewhere in Pennsylvania
  • Long forested mountain ridges; forests include oak-hickory-hard pine communities
  • Aspects of regional geology and soils (shale, etc.) support important endemic habitats

Conservation Targets

  • Five Biological Diversity Areas, totaling 23,000 acres of important habitats , such as old growth hemlock and riparian forest communities
  • 40 occurrences of globally rare plants, invertebrates and vertebrates including harperella and Kate’s Mountain clover (two herbaceous plants associated with stream valleys), and a number of unusual moth and dragonfly species
  • Ecologically significant natural communities, including shale barrens and mountain top barrens
  • Nine important forest patches totaling more than 60,000 acres
  • 350 miles of stream ecosystems, including high quality creeks to protect and other stream segments important as restoration objectives

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