We present the first summary of the status and distribution of the Benton cave crayfish (Cambarus aculabrum). The range of this endangered crayfish is limited to 4 sites globally (3 in Benton County and 1 in Washington County, Arkansas). The identity of the species at these 4 sites is based upon morphological and genetic studies. The identities of cave crayfish inhabiting 2 additional Benton County sites remain undetermined. The current population census is 40 individuals. Threats to the species are analyzed, and subsequent conservation measures recommended. Habitat degradation remains a threat to the species, especially for water quality. Analyses from 1983 to 2002 document nutrient pollution of the subterranean stream habitats, originating from sources such as septic system discharge and run-off from confined animal feeding operations.