The Edwards-Trinity Aquifer System of Texas, USA, one of the world's most ecologically diverse groundwater systems, contains 14 species (across seven genera) of small, poorly studied freshwater snails. Their underground habitat and microscopic size make them difficult to study and identify. Most published records are from original species descriptions, and some have not been seen since they were described more than 100 years ago. Here we use ∼150 new collections, including spring and hyporheic zone sampling from across the Texas portions of the Edwards-Trinity Aquifer System, to update the ranges of these species. Two species were very uncommon, if encountered at all; individuals that might be Phreatodrobia imitata were seen at one sampling location, and a single individual of P. punctata was encountered once. The most frequently encountered snail, P. nugax, can be highly abundant and is found across a wide range. Other notable findings include the rediscovery and greatly expanded range of Stygopyrgus bartonensis, the Barton Cavesnail, as well as range extensions of 100 km or more for several species.