- Don's Views Visit amazon.com through our bookstore and help SDEF. S.D.E.F Bookstore 2002 Wild Flower Walkabout Severson Dells is a nature education center located four miles southwest of Rockford Illinois, U.S.A. (map) With 204 acres of mixed woodlands, prairie, wetlands, and oldfield habitat, Severson Dells is an ideal setting for nature study and appreciation. A SENSE OF PLACE, BELONGING & ...www.seversondells.org