Geology per se may not be the first thing on your mind when reveling in the beauty of Cades Cove, that famous mountain basin that ranks among the most popular attractions in Great Smoky Mountains National Park. Of course, the geology’s responsible for the lovely scenery, but your average visitor isn’t thinking about rock layers—just soaking up the vistas, delving into the incredibly fascinating history on display via 19th-century structures, and keeping an eye out for the abundant wildlife.
But, as the grandeur of the setting suggests, there is quite the engrossing geologic story here, and one of its most tantalizing expressions is Gregory’s Cave. That well-known cavern, the interior of which is off-limits to the public without special permission from the National Park Service, is the focus of this here review, but first let’s set the scene with a cliff-notes version of Cades Cove geology!
If we think about geologic layers at all, we usually assume older rock lies beneath younger rock. Well, not always: Faulting and other processes sometimes result in older rock ending up sitting atop a younger rock. That’s happened in places in the Southern Appalachians.
In the Cades Cove area, long-ago faulting thrust older rock of Precambrian vintage over younger Paleozoic limestones and shales. Then erosion, performed for example by eons of running water, stripped away the overlying rock to reveal, in places, the more youthful bedrock underneath. This exposure is called a tectonic “window” (or, after the German word, a “fenster”). Cades Cove is such a window, as are a number of other similarly flat-floored, roughly oval-shaped basins in the area, such as Tuckaleechee, Wears, and Miller coves.
Rainwater percolating down through the limestone-dominated “karst” bedrock of these coves allowed for chemical weathering of these reactive formations, enlarging fissures and dissolving passages to form sinkholes, caverns, and caves. Two particularly substantial ones lie in and around Cades Cove: Bull Cave, said to be the deepest in Tennessee, and—drumroll, please—Gregory’s Cave, right on the edge of the Cove.
Little is known about where the “Cades” of Cades Cove comes from, and indeed some have suggested the original Euro-American name for the basin might have been “Cave Cove,” in reference to Gregory’s Cave, with “Cades” being a later distortion.
Gregory’s Cave sits on (or, rather, in) the southwestern flanks of the aptly named Cave Ridge on the north side of Cades Cove. Cave Ridge rises to meet the larger Tater Ridge, which mounts northeastward to the heights of Double Mountain and then 3,686-foot Cerulean Knob.
A stone’s throw, relatively speaking, from the John Oliver Cabin—the oldest standing structure in Cades Cove—Gregory’s Cave is a subterranean karst portal with a main, roughly straight passageway some 430 feet or so long. A side passage that splits off from it runs about 120 feet. The opening of Gregory’s Cave is approximately four feet high and 10 feet across; the main passageway is an average of 16 feet high and ranges between about 20 and 56 feet wide. Stalactites, stalagmites, and other formations mark its depths, which for much of the year include standing pools.
The cave is named for the Gregory family who lived here prior to the establishment of Great Smoky Mountains National Park (and, indeed, members of the family stayed on the property awhile after permission of the Park Service). For a while they used the cave—which doubled as a “fallout shelter” for Cades Cove residents—to store provisions, but, in 1925, they opened it up to the public as a tourist attraction. As part of that commercial endeavor, the Gregory family added battery-powered lanterns and other improvements to the cave. When the national park was established, Gregory’s Cave was closed down.
There’s yet older human history evoked in Gregory’s Cave: Its passageways include evidence of 19th-century saltpeter mining, and at its back, there’s an image that has been interpreted as an American Indian petroglyph of a wild turkey—“the only visible evidence of prehistoric use of caves in the park by Native Americans,” a Park Service document states.
The cave is also a biological wonder, host to an array of salamanders, frogs, and invertebrates—including a cave-dwelling amphipod (a kind of crustacean) found nowhere else. In addition, more than 1,000 bats winter in Gregory’s Cave.
As we said at the outset, Gregory’s Cave is closed to public entry: Metal bars prevent access to the interior, open only to those with permission from the Park Service (mainly researchers).
You can, however, view (and photograph) the outside of the cave—which is marked on the U.S. Geological Survey topographic map for the area—by walking there from the vicinity of the John Oliver Cabin. A pretty conspicuous gated-off dirt road leads the way. Follow it a short way, passing some old picnic tables—remnants of a formerly used park amphitheater area—before, just a little beyond, coming upon the cave to the righthand side. The entrance—barred just inside—is tucked within a grotto-like outcrop.
You’ll know when you’re in the vicinity of the entrance to Gregory’s Cave on the dirt road when you see some trees with bat boxes attached to them.