Jon J. Duerr, namesake of South Elgin forest preserve, dies Conservationist Jon J. Duerr, for whom a South Elgin forest preserve was named, died Feb. 13 at the age of 81. Duerr served in various roles for the Forest Preserve District of Kane County over 19 years, including assistant superintendent, superintendent, director of field services and, from October 2002 through June 2004, executive .