The Piedmont is an ecological and physiographic region that forms a tapering band along the eastern United States, from central Alabama to the doorstep of New York City. Bound on one side by the Fall Line, where river rapids mark the transition between the sediments of the Coastal Plain to the harder rocks of the interior, and on the other by the wall of the Blue Ridge, this is largely a land of gently rolling terrain, red clay soils, and forests of oak, hickory, and pine. Over the four centuries and more since Europeans first laid eyes on the Piedmont, the region has taken on many aspects. For the first few generations of colonists it was a forbidding wilderness, the terra incognita that began where rivers became impassable and stretched all the way to the mountains and the limits of the known continent. Today it is a thoroughly explored, settled, and altered landscape, the setting for some of America’s largest urban areas — including, fully or in part, those of New York, Philadelphia, Washington, Richmond, Raleigh, Charlotte, and Atlanta. It is a subtle landscape, lacking the eye-catching landmarks provided by mountains and seacoasts, and we denizens of the region are often guilty of ignoring the terrain and ecosystems in which we are embedded. Yet for all its superficial plainness, the Piedmont is a region of startling richness and diversity. The rocks beneath our feet, including some of the oldest in the United States, are a bewildering patchwork bearing witness to a billion years of continental rifts and pileups. These are largely gneisses and other metamorphic rocks that were pressure-cooked during the creation of great mountain ranges — some of which in their day gave the Piedmont the character of today’s Himalayas. But the region’s complex history of tectonic collision and separation left behind a host of fascinating incongruities, including sedimentary basins dotted with dinosaur footprints, vast lava flows squeezed and uplifted into fertile hills, and hidden seams of exotic rocks like serpentinite. This geological diversity has given rise to a corresponding diversity of ecosystems. Outcrops of granite, diabase, and other rocks support glades and barrens where ultra-rare species flourish on extreme soils. Unusual grasslands and shrublands cling to existence along our tumbling rivers, in channels scoured by floods. Along stream bluffs and the flanks of monadnocks (isolated hills made of tougher rock than the surrounding terrain), cool microclimates offer a refuge to hemlocks and other northern flora. And quirks of topography and drainage produce ephemeral ponds relied upon by a long lineup of frogs, turtles, and salamanders. Few landscapes have been so comprehensively transformed as the Piedmont. The suppression of fire has eliminated vast swaths of grassland and savanna and banished large animals like bison and elk. The damming and channeling of rivers has erased exceptional wetland communities and walled off the ancient routes of migratory fish. Hunting, forest clearance, and invasive pests have sealed the fate of the wolf, the passenger pigeon, the American chestnut, and other species that were once emblematic of the region. Yet experts and citizen scientists from New York to Alabama are hard at work, preserving and cataloguing what remains and restoring what has been neglected. There has never been a better time to get to know the Piedmont.
Pan and zoom on the map below to explore the Piedmont in rich detail. Check the boxes at right to toggle layers, and click on visible features on the map for more information. (Some layers may not be visible at all scales.)