CHAPTER 13 Middle Schuylkill River Conservation Landscape The confl uence of the Perkiomen Creek and the Schuylkill River is at the center of the Middle Schuylkill River Conservation Landscape. The landscape includes the riparian corridor along the Schuylkill River from Port Kennedy to just below Royersford. Floodplains and forested cliffs and ravines along the river are signifi cant natural features. Valley Forge National Histori- cal Park, the John James Audubon Center at Mill Grove, and the Oakes Reach of the Schuylkill Canal are important historical resources. Description Location The Middle Schuylkill River Conservation Landscape occupies 6,451 acres including parts of Upper and Lower Providence and Upper Merion Townships and extends up the Perkio- men Creek to Yerkes. It adjoins the Skippack Creek Conservation Landscape and the Middle Perkiomen Creek Corridor (Figure 13.1). Core areas include Valley Forge National Historical Park and the John James Audubon Center at Mill Grove. Other publicly owned tracts include Lock 60 and the Oakes Reach of the Schuylkill Canal, Upper Schuylkill Valley Park, and Lower Perkiomen Valley Park. The Perkiomen Trail connects with the Schuylkill River Trail within this landscape. Another connection is with the Horseshoe Trail, which starts at Valley Forge National Historical Park and extends through Chester County to the west. The Montgomery County open space plan also envisions a trail along Skippack Creek connecting with Evansburg State Park. Hydrology This landscape is entirely within the Schuylkill River drainage basin. It includes the mouth and lower reach of the Perkiomen Creek, as well as several small tributaries that enter the Schuylkill River on the northeast side. The Schuylkill and Perkiomen are designated as WWF MF (warm water fi shery, migratory fi shes). To the southwest, Valley Creek, the county’s only EV stream (exceptional value), which forms the border with Chester County, is the only signifi cant tributary. Fish ladders are in place at the Fairmount and Flat Rock Dams, and one is under construction at Norristown Dam. A fourth ladder is planned for Black Rock Dam in 2008. These fi sh ladders will further facilitate the upstream movement of migrating shad, which have already been de- tected after a gap of many years. Wetlands are present along the Perkiomen Creek on the Mill Grove site and in the fl oodplain of the Schuylkill River. Impoundment basins, created as part of the river cleanup in the late 1940s, are located along the Schuylkill in Valley Forge National Historical Park and just below Port Providence on the north side of the river. Natural Areas Inventory Update 2007 207 208 Natural Areas Inventory Update 2007 Natural Areas Inventory Update 2007 209 210 Natural Areas Inventory Update 2007 Natural Areas Inventory Update 2007 211 Geology North and east of the Schuylkill River the geology consists of consecutive bands of Newark Basin Triassic sediments including Stockton Formation sandstones, shales and siltstones; Locka- tong argillites; and Brunswick shales from south to north respectively (Figure 13.2). Where the harder argillite intersects the Schuylkill in the vicinity of Mont Clare, the river forms a dramatic loop with steep cliffs and deeply etched side ravines that defi ne the river valley. The Stockton Formation extends on the southwest side of the river where the southern edge of the Newark basin meets a complex of much older rock including Wissahickon schist, Chickies quartzite, and Ledger and Conestoga Formation limestones in Valley Forge National Historical Park. Port Kennedy Cave, located in a lobe of the Ledger Formation limestone that extends to the river on the south side, is identifi ed as an important geological feature because of the unusual assemblage of Pleistocene era fossils found there. Originally exposed by limestone quarrying, the site was excavated between 1870 and the 1896 when water seeping in from the river forced a cessation of work. The cave produced a huge number of specimens including saber-toothed ti- ger, giant ground sloth, mastodon, giant cave bear, short-faced skunk, horse, tapir, mountain lion, coyote, wolverine, badger and black bear. The specimens are housed at the Academy of Natural Sciences of Philadelphia. In the early 20th century the site was fi lled in with asbestos-containing waste from the near- by magnesia manufacturing operation and the exact location became obscured. However a recent study of historical documents and local topography has resulted in re-establishing the precise location. Forest Cover Forests cover 2,505 acres of this landscape, 39 percent of the total land area; of that total 1,023 acres qualifi es as interior forest and 78.8 acres is riparian forest (Figure 13.3). Critical Features The Middle Schuylkill Conservation Landscape includes one priority site identifi ed in the 1995 Natural Areas Inventory: Mont Clare Cliffs and Ravines. PNHP-listed species confi rmed to be present in the landscape include redbelly turtle and two plants: toothcup and a species of dod- der (Cuscuta campestris). Extensive riparian habitat along the Schuylkill River and the Perkio- men Creek are critical to the diversity of species found in the landscape, especially reptiles and amphibians and birds. Birds – See data for Valley Forge National Historical Park below. Reptiles and Amphibians – See lists for Valley Forge National Historical Park and Mont Clare Cliffs and Ravines below. Past Uses The industrial and transportation history of the Schuylkill River corridor is discussed in the 212 Natural Areas Inventory Update 2007 introduction to this report. The Oakes Reach and Lock 60, a preserved section of the Schuylkill Canal, lies along the east side of the river between Port Providence and Oakes. Several copper and lead mines were located in the vicinity of the village of Audubon as early as 1780. A lead mine at Mill Grove reportedly furnished bullets for the Continental Army. By the mid 1800s, both lead and copper were being mined at several additional mines located along Mine Run on both sides of Egypt Road. Valley Forge National Historical Park was the site of the Revolutionary Army encampment dur- ing the winter of 1777-1778. Preservation Status and Other Designations The Schuylkill River National and State Heritage Area includes the Middle and Upper Schuylkill Conservation Landscapes as defi ned in this study. Designated by the state in 1995, the Heritage Area became a joint project of the National Park Service and the Pennsylvania Department of Conservation and Natural Resources in 2000. It is managed by the Schuylkill River Greenway Association. The Schuylkill is also des- ignated as a Pennsylvania Scenic River. Protected lands within the landscape include 3,452 acres of Valley Forge Historical National Park (1,964 acres in Montgomery County) and 427 addi- tional acres of county parklands (Fig- ure 13.4). Andruss Island, a 26.9-acre island in the Schuylkill River is owned by The Natural Lands Trust. Mill Grove, the home of John James Audubon, is listed on the National Reg- ister of Historic Places. The Schuylkill Trail in Valley Forge National Park Core Areas Valley Forge National Historical Park At the time of the Revolutionary War encampment the landscape around the forge on Valley Creek was agricultural. Farms averaged 189 acres in size and were divided into small, fence- enclosed fi elds of 1 to 10 acres. Wheat was the main cash crop, but a variety of other grain and vegetable crops were also grown. To this day, fencerows in the park represent the property lines from the encampment era. Park management has attempted to represent the agrarian landscape of the late 1700s with meadows. When the Continental Army arrived, about one-third of the area was still forest-covered. Data from early deed descriptions (witness trees) indicate a forest dominated by white and black oak, and hickory with some chestnut. During the encampment nearly all of the trees were cut Natural Areas Inventory Update 2007 213 for fuel or building material. Present day forested areas contain trees that have grown since the historical period. Plant Diversity – Several records of Pennsylva- nia Natural Heritage Program-listed plants exist for the park. A large population of toothcup is present in the impoundment basin on the north side of the Schuylkill River; a rare species of dodder is present at the same site. American holly grows on the slope below the chapel; tawny ironweed once grew on Mount Joy, although its current status is uncertain given the level of deer browse. A stand of possum-haw was present along Valley Creek, protected from deer by a fence. The meadows were thought to have included a population of a rare sedge Toothcup at Valley Forge National Historical Park (Carex gravida); but subsequent re-examination of the specimens deposited in the herbarium of the Academy of Natural Sciences of Philadelphia has revealed that they were misidentifi ed specimens of the more common Carex aggregata. Plant Communities – Classifi cation and mapping of vegetation types was carried out by The North Carolina State University Center for Earth Observation and the Pennsylvania Science Offi ce of the Nature Conservancy under a contract with the National Park Service in 2005. No regionally rare plant communities were found in the park; the single most common vegetation type was grassland at 32.3% of mapped area. Successional forest occupied 11.4% of the study area and tuliptree – oak forest 6.8%. Natural vegetation quality within the park was described as fair to poor due to heavy deer browse, which has created depauperate herb and shrub layers and eliminated forest regenera- tion. Successional forests and other areas that have been disturbed recently are also severely impacted by invasive, non-native species. See Table 13. 1 below for a list of vegetation types described for the park.