Lehigh Valley South Mountain
These rocky, wooded hillsides dominate the natural landscape of southeast Lehigh County.
Lehigh Valley South Mountain Conservation Area within the Pennsylvania Highlands
Part of the Reading Prong geological formation, Lehigh Valley South Mountain consists of a narrow band of crystalline rock that runs along Saucon Creek. This conservation area is surrounded by urban areas and suburban sprawl, making it an important open space to conserve. The cities of Allentown and Bethlehem and the boroughs of Emmaus and Hellertown, with a total population of more than 200,000, share the slopes of the mountain.
Natural Resources
Several waterways flow from Lehigh Valley South Mountain to the Lehigh River. Saucon Creek flows through gaps in this region, and Trout Creek and Black River have their headwaters on the mountain.
Lehigh Valley South Mountain contains a state significant area identified by the Natural Heritage Inventory of Lehigh and Northampton Counties, Pennsylvania – Update 2013, the Robert Rodale Reserve. The forested habitat of this reserve supports skunk cabbage, forest seep wetland communities, and populations of three plant Species of Special Concern by the Pennsylvania Natural Heritage Program. The landscape contains scattered bedrock outcrops and several vernal pools that are important breading habitat for amphibians.
A Pennsylvania Heritage Geological Site, Bauer Rock, is found here. It is a mass of gneiss of the Precambrian-aged Pochuk Formation. The rock stands more than 40 feet above the ridgeline, providing visitors a panoramic view of the Saucon Valley below.
Historical / Cultural Resources
Historically, this region supported an agricultural way of life. This area was first settled by Europeans in the 1720’s. The first public road into the Lehigh Valley, King’s Highway, passed through Liebert’s Gap. In 1734, settlers established a way station for travelers, the “zufluchtshaus” or “Shelter House”, still a popular historical destination.
The mining of iron ore on Lehigh Valley South Mountain began in 1809. The greatest activity was from the end of the Civil War to about 1885. In 1880, Pennsylvania led all states in the production of iron ore, and Lehigh County led all the counties in the state. The availability of iron ore as well as trees to make charcoal to fire the iron furnaces helped give rise to the Industrial Revolution of the Lehigh Valley.
Recreational Resources
Today, 300 years after the first European settlement, the Lehigh Valley South Mountain is still playing a major role in the lives of Pennsylvanians. This dramatic geological feature, complete with mineral riches, flora and fauna, and life-sustaining water, is of particular value for both its biodiversity and the recreational opportunities it provides for the heavily developed eastern Pennsylvania area. There are many recreational opportunities within the Lehigh Valley South Mountain landscape. Many waterways provide for fishing, paddling, and boating activities. The South Mountain Alpine Street trailhead also provides access to multiple hiking and mountain biking trails.
Interactive Map
The Lehigh Valley South Mountain conservation area is located in Lehigh and Northampton counties. It has a total acreage of roughly 5,785 acres with approximately 1,198 acres of protected open space that the public can access, plus 8 miles of hiking trails. This region is known for the South Mountain Preserve , Bauer Rock , and Shelter House.
Lehigh Valley South Mountain
Local Organizations
Follow the links below to learn more about some organizations in the region that focus on conservation and land protection.
Call to Action
Join us in advocating for the protection of the mountains, rivers, forests, and trails of our region.
Programs and people dedicated to conservation in Pennsylvania ensure the region’s outdoor resources are managed responsibly. Click below to speak up and urge your state legislators to increase conservation funding.
Increase State Conservation Funding
Return to The Pennsylvania Highlands Conservation Atlas main StoryMap where you can discover and continue to learn about the other Pennsylvania Highlands Conservation Areas in the Next Steps section.
