Lee County Cave Isopod (Lirceus usdagalun).

On February 19, 2002, five staff from the Service and the Virginia Department of Conservation and Recreation's Division of Natural Heritage rediscovered the Lee County cave isopod in Thompson Cedar Cave, where the tiny crustacean was thought to be extirpated. The Lee County cave isopod was listed as endangered in 1992 and is known from only the Thompson Cedar Cave type locality and one other cave and two springs located in the unique limestone karst topography of southwestern Virginia.

The isopod population and the cave wildlife community were thought to be extirpated from Thompson Cedar Cave by 1988 due to leachate from a huge sawdust pile that was deposited in and around the cave entrance. In response to concern from the Service and several state agencies, the sawmill operator voluntarily removed the sawdust from the sinkhole surrounding the cave entrance and installed a clay berm to divert surface runoff from the sinkhole. According to an inventory conducted in late June by biologists from the Service and the state Division of Natural Heritage, the Lee County cave isopod population in Thompson Cedar Cave is growing and the remaining ecological community of the cave seems to be thriving. We believe that the removal of the sawdust from the sinkhole surrounding the cave entrance and recent drought conditions have slowed the release of leachate to the subterranean system, allowing the cave community to recover. The Service and several partners are assisting the lumber company in removing the remaining sawdust.