525 ILCS 30/13

An owner of a nature preserve retains custody, administration and management thereof, or may assign, lease or convey an interest or ownership therein, or contract for the custody, maintenance or operation thereof, subject to the instrument of dedication, the policies of the Commission, the rules, the plan and this Act. The Department, the Commission and others may participate in management or custody of a nature preserve as provided by the instrument of dedication or the rules.