From 2002 to 2018, we conducted 525 events to survey bats (nights of mist-netting and visits to bridges, mines, caves, etc.) and captured or observed 6119 bats, including all 9 species that regularly reside in Iowa. Our captures include a total of 142 new county records, and we located an additional 11 county records in specimens deposited in museums; we present at least 8 county records for each species in the state. Since the geographic distributions of most species span the entire state, many of these county records simply fill in gaps within hypothesized distributions. Records for Lasionycteris noctivagans, Lasiurus borealis, Myotis lucifugus, Myotis septentrionalis, Myotis sodalis, Nycticeius humeralis, and Perimyotis subflavus, however, extend the known range for these species or fill large gaps in their suspected distribution. Additionally, our captures provide evidence of reproduction occurring across the state for most species. Previously, little information had been published on the geographic extent of reproduction for bats in Iowa. Lastly, we report new information regarding timing of seasonal activities for bats in Iowa. For most species, we present new early and/or late records for lactation, postlactation, appearance of flying young, and flight activity outside of hibernation. Collectively, these records expand our knowledge of the biology of bats in Iowa.