The only previous reported record of eastern small-footed bats (Myotis leibii) in Illinois was from a 2005 discovery of two individuals under a rock at the Fink Sandstone barrens of Shawnee National Forest (SNF). In Jun. 2011, the U.S. Fish and Wildlife Service requested information on the species to review potential listing under the Endangered Species Act. In response, managers at the SNF initiated a survey to determine if a resident population of eastern small-footed bats exists on the forest. We surveyed the SNF within Pope and Johnson Counties from 25 Jul.–16 Aug. 2011 by searching for day roosts under loose rocks on exposed rock outcrops. We discovered 29 individuals, including post lactating females and juveniles, along rock outcrops surrounding the 2005 site. While, the extent of M. leibii occurrence in Illinois is still poorly understood, our survey suggests that a resident breeding population occurs within the southern tip of the state.