We attempted to identify salamanders from the Cumberland Plateau of Tennessee that have been referred by previous investigators to Desmognathus ochrophaeus. We compared variation at 22 allozyme loci in 10 populations to allozymic variation in other desmognathines. Multidimensional scaling, cluster, and parsimony analyses indicate that populations from our southernmost localities in the plateau are referable to D. ocoee, whereas the northernmost populations are D. ochrophaeus. In contrast, animals sampled from the middle of the plateau are genetically very distinct from all members of the complex and represent a new species described herein as Desmognathus abditus. D. abditus exhibits very limited gene exchange with D. ocoee and D. ochrophaeus where it contacts those forms. A population from the Eastern Highland Rim that has previously been referred to D. ochrophaeus may represent yet another undescribed species. The southern Cumberland Plateau clearly represents an area of substantial desmognathine diversity.