From the Illinois Natural History Survey, the _Field Guide to Amphibians and Reptiles of Illinois_ is designed for use by students, naturalists, biologists, land managers, law enforcement officials, and others. One goal of the Guide "is to help the reader learn about all 102 species of amphibians and reptiles that live within the boundaries of Illinois. Basic information is presented on their biology and life history, as well as a brief discussion of the species that are listed as threatened or endangered under the state's Endangered Species Protection Act." This complete online version of the Field Guide connects visitors to species accounts with good photographs; distribution maps; and brief entries on Description, Habitat, Status, and more. The Guide also contains downloadable keys to reptiles and amphibians of Illinois, and a Glossary of Terms.