Townsend’s big-eared bats (Corynorhinus townsendii) are widely distributed in the western United States and largely dependent on subterranean roosting habitat (e.g. abandoned mines and caves) in much of their range. However, information about mechanistic roosting associations is largely based on spatially and temporally limited data. Since this species is a conservation priority across much of the U.S., it is critical to understand patterns and drivers of roost occupancy and use at biologically appropriate spatial scales. To close this knowledge gap, we compiled a database of over 3600 Nevada roost surveys (e.g. abandoned mine surveys) conducted between 1989 and 2021. Three hundred-seventy of the sites (10.6%) were occupied by at least one C. townsendii individual at the time of survey, indicating day roosting habitat. Hundreds of additional sites showed probable night roosting or periodic day roosting by C. townsendii as evidenced by presence of guano and/or moth wings. Preliminary statistical analyses (Akaike Information Criterion) indicate that aspect of portal opening and elevation of portal are the most robust indicators of use. Further statistical analyses will be conducted to elucidate the relative importance of roost site versus landscape characteristics on predicting occupancy and use.