Stephen M. Pescitelli is retired from the Illinois Department of Natural Resources, where he spent thirty years as a Natural Resources Advanced Specialist and stream biologist. He was responsible for monitoring fish assemblages in the watershed areas of the Des Plaines, DuPage, Fox, Kankakee, and Mazon Rivers as well as the Aux Sable Creek. He was also involved in stream restoration, focusing on dam removals in northeastern Illinois. He also worked and studied at the Illinois Natural History Survey.