National Natural Landmarks in the Potomac Heritage NST corridor

Within Ohiopyle State Park the 100-acre Ferncliff Peninsula Natural Area is one of the best examples of a typical late-succession forest in the Allegheny Mountains. It contains a unique habitat of unusual plants, colorful wildflowers, and ancient ferns found only in the warmer southern regions. The microclimate of the river gorge allows these plants to survive.

 

Sugarloaf Mountain, near Dickerson, MD, provides evidence regarding age and structural relationships of rocks in the Piedmont biophysiographic province. The site appears to be either an outlier to the east of the main mass of the Catoctin Mountain, or a root remnant of the ancient Appalachia land mass. Sugarloaf is an example of a monadnock, a geologic feature where a more resistant rock base, such as quartzite, is left behind as surrounding rock erodes away. Quartzite was historically quarried at Sugarload and used to construct the Monocacy Aqueduct on the Chesapeake and Ohio Canal.

 

Caledon State Park, on the tidal Potomac River east of Fredericksburg, VA, includes one of the best examples of oak-tulip poplar-dominated virgin upland forest in the nation. This area has now become an important site for conservation, especially for bald eagles, that are a common site throughout the park.

 

Cranseville Swamp is located in a "frost pocket," an area where the surrounding hills capture moisture and cold air that conspire to create a landscape more reminiscent of habitat found much further north in Canada. Some of the boreal bogs that formed thousands of years ago have survived, offering a glipse into ice ages past.