The Tumbling Creek Cavesnail is a tiny, eyeless, and unpigmented aquatic snail found only in the stream within Tumbling Creek Cave in Taney County, Missouri, making it one of the most geographically restricted species in the United States. The species lives on the undersides of stones in clear, fast‑moving, silt‑free cave stream habitats and feeds on biofilm connected to energy inputs from the cave’s gray bat colony. Once numbering in the thousands, the population declined sharply beginning in the 1990s due to habitat degradation from increased siltation, reduced water quality in the cave’s recharge area, and predation by invasive ringed crayfish. Although conservation efforts—including habitat restoration, crayfish control, and installation of surrogate substrates—have improved water quality and stabilized conditions in parts of the cave, the species remains at extremely low abundance and is federally listed as endangered.