6 
John R. Holsinger and David C. Culver 
Fig. 3. Part of the eastern United States showing major physiographic 
provinces as follows: 1, Coastal Plain; 2, Piedmont; 3, Blue Ridge; 4, 
Appalachian Valley and Ridge (= Appalachian Valley); 5, Appalachian Plateau; 
6, Interior Low Plateaus. 
geographic isolation. Although these karst areas are situated within the 
Appalachian Plateau proper, they are geographically close and 
geologically similar to belts of cavernous limestone on the western side 
of the Appalachian Valley. 
In Alabama, Kentucky, and Tennessee, where the Appalachian 
Plateau is known locally as the Cumberland Plateau, cavernous 
limestones of Mississippian age are exposed along the highly dissected 
western margin of the Plateau in all three states. Cavernous areas on the 
western side of the plateau, unlike those on the eastern side, are closely 
