NPS Geodiversity Atlas—Cumberland Gap National Historical Park, Kentucky, Tennessee, and Virginia


cumberland gap report cover with landscape image

Geologic Features and Processes

Cumberland Gap National Historical Park preserves a geologic and landform feature that was a vital gateway to the west during the early expansion of the United States. The gap is a deep notch across the otherwise continuous ridge of Cumberland Mountain. Additional geologic features, such as the White Rocks, guided early settlers moving westward on the Wilderness Road. The gap was a strategic outpost during the American Civil War, alternately occupied by Union and Confederate troops. And, it continues to be a valuable transportation corridor today.

Cumberland Gap is part of a regional geologic structure called the Pine Mountain thrust sheet created during the last major mountain building event of the Appalachians—the Alleghany Orogeny.

The park’s rugged landscape is fashioned from rocks originally deposited in or near shallow seas. During Appalachian mountain-building approximately 300 million years ago, these rocks were folded, faulted, and shoved up and westward along the Pine Mountain thrust fault, forming the Middlesboro syncline to the west and the Powell Valley anticline to the east. Hundreds of millions of years of subsequent erosion beveled the ancient mountains, leaving behind limestones in Powell Valley, resistant ridges of sandstone at Cumberland and Pine Mountains, and stream dissected upland areas near Middlesboro.

Cumberland Gap is the primary geologic feature in the park. Its location is tied to an ancient fault—the Rocky Face Fault—formed prior to the last major Appalachian Mountain-building episode. Fractures and deformation associated with movement along this fault weakened the rocks. Over time, the fractured rock eroded away, forming a gap.

The circular Middlesboro basin, adjacent to the park and easily visible from the Pinnacle Overlook, contains intensely deformed rock—evidence of an ancient meteorite impact.

Paleontological Resources

Paleontological resources in the park include abundant marine fossils found throughout the limestone (from ancient seas hundreds of millions of years old) as well as much younger remains (tens of thousands of years old) found in caves and sink holes.


Cave and Karst

Cumberland Gap National Historic Park contains a significant karst landscape composed of mostly Mississippian age (360-318 million years old) limestone. With 30 known caves, other karst features include sinking streams, pits, sinkholes, and springs. Gap Cave is the longest known cave in the park at over 18 miles of surveyed passages and still going.

Gap Cave Spring was a significant water source for early settlers moving through Cumberland Gap.

Cumberland Gap was a strategic location during the Civil War. The area and Gap Cave traded hands several times. Important graffiti with interesting names, dates, and drawings are found in Soldier’s Cave (part of Gap Cave) from both Union and Confederate forces.

All NPS cave resources are protected under the the Federal Cave Resources Protection Act of 1988 (FCRPA)(16 U.S.C. § 4301 et seq.).

Abandoned Mineral Lands

Coal and iron-ore mining have been important regional industries for more than 100 years and continue today. Smaller-scale quarrying of limestone and sandstone also occurs. Disturbed lands within the park—old (ca. approximately 1900) coal mines and iron mines, potassium nitrate mines, abandoned haul access roads, and a few sand and gravel quarries—were not large-scale mines or quarries, but do attest to the importance of mining to the history of the Cumberland Gap area (Englund 1964; Thornberry-Ehrlich 2008).


Geology Field Notes


Regional Geology

Cumberland Gap National Historical Park is a part of the Appalachain Plateaus Physiographic Province and shares its geologic history and some characteristic geologic formations with a region that extends well beyond park boundaries.

Maps and Reports

Geologic Resources Inventory


Source: Data Store Saved Search 2798. To search for additional information, visit the Data Store.

Soil Resources inventory

NPS Soil Resources Inventory project has been completed for Cumberland Gap National Historical Park and can be found on the NPS Data Store.

Source: Data Store Saved Search 2836. To search for additional information, visit the Data Store.

Related Articles

Cumberland Gap National Historical Park

National Park Service Geodiversity Atlas


For more information on the NPS Geodiversity Atlas, contact us.