Due to the presence of sensitive species and dangerous conditions, visitation to Unthanks Cave is permitted only for scientific research. One of Virginia's largest caves, Unthanks Cave has been placed on the Virginia Cave Commission's list of "significant caves" and rated as one of the state's top caves in the areas of biology, geology, hydrology, size and aesthetics. Massive speleothems, such as stalactites, stalagmites, columns and rimstone, punctuate the bizarre, natural architecture of its seven miles of mapped passages. The preserve protects the only known entrance to Unthanks Cave.
Unthanks Cave houses an unusually diverse animal community, comprised of cave-adapted species (troglodytes); among these are a number of rare invertebrate species endemic to only a handful of caves in southwestern Virginia. There are also relatively large populations of Powell Valley planarian, the Southwest Virginia cave isopod, and a cave-adapted species of Carabid beetle. In addition, two Hydrobiid snails, which represent new species, have been collected from Unthanks Cave.
The cave was purchased by the Conservancy in 1987 to protect the unique species that live there. Prior to the acquisition, the previous owner approved the formation of a committee to manage the cave. Several prominent biologists, such as Dr. John Holsinger of Old Dominion University and Dr. Robert Hershler of the Smithsonian Institution, initiated studies of the unusual cave fauna.
The Conservancy is researching the unique species present in the cave. Cave protection is one of the goals of the Conservancy's Clinch Valley Program.