Gill-breathing operculate snails (Gastropoda: Prosobranchia) were reported historically from streams and wetlands throughout eastern Kansas. The past century has witnessed declines in the geographic range of most native taxa and the probable extirpation of at least two species, Campeloma crassulum and Amnicola limosus. Recent investigations have documented populations of five remaining prosobranch species. These include Probythinella emarginata, previously known in Kansas solely from the Pleistocene fossil record, and Pleurocera acuta, last reported in the state in 1956. Cincinnatia integra remains the most widely distributed prosobranch snail, occurring in scattered colonies throughout much of eastern Kansas. Pomatiopsis lapidaria, Elimia potosiensis, P. emarginata, and P. acuta are each relegated to a single known marsh or stream drainage. Earlier reports of Campeloma decisum in Kansas now are attributed to the conchologically similar species, C. crassulum. Changes observed in the prosobranch fauna during the past century have paralleled historical declines in habitat availability and surface water quality. The reversal of these environmental trends should serve as the initial focus of snail recovery efforts in Kansas.