Until recently it was believed that the population of eastern woodrats (Neotoma floridana) in Pine Hills, Union County, Illinois, represented the only extant population remaining in the state. Trapping at sites formerly occupied by woodrats and in areas with suitable habitat resulted in the documentation of additional populations at Fountain Bluff, Little Grand Canyon, and Horseshoe Bluff, Jackson County. Woodrats currently are more numerous and have a wider distribution in southern Illinois than previously believed.
Monty, Anne-Marie, Wagle, Elizabeth R., Emerson, Robert E. and Feldhamer, George A. "Recently Discovered Populations of Eastern Woodrats (Neotoma floridana) in Southern Illinois." (Jan 1995).