We located the endangered rock vole, Microtus chrotorrhinus, at 3 of 59 sites in mixed mesophytic forests in the southern Appalachians. Rock voles were always found within mixed mesophytic habitats characterized by yellow birch, Betula alleghaniensis, rather than mixed mesophytic habitats dominated by other tree species. We compared the tree communities, microhabitat features, and small mammals found within three groups of habitats: sites where M. chrotorrhinus was found, yellow birch habitats where M. chrotorrhinus was not found, and other mixed mesophytic habitats where M. chrotorrhinus was not found. Sites occupied by M. chrotorrhinus had greater amounts of large, rocky substrate, greater incidence of moss, and a more northwest aspect than yellow birch and other mixed mesophytic sites without M. chrotorrhinus. Moreover, sites with rock voles had larger trees and were significantly older than sites without M. chrotorrhinus. Red-backed voles, Clethrionomys gapperi, are readily sampled by live-trap methods and were significantly more abundant at sites with M. chrotorrhinus, and may thus be a promising indicator species. Our results suggest that mixed mesophytic forests, especially older stands dominated by yellow birch and rocky substrate, should be managed with care to preserve M. chrotorrhinus habitat.