Kane county forest preserve district under thier rules & regulations ony has a prohibition on hunting. But if you can render an unofficial legal interpritation of the following statute I believe has been discussed before.
(720 ILCS 5/21-6)
Sec. 21-6. Unauthorized Possession or Storage of Weapons.
(a) Whoever possesses or stores any weapon enumerated in Section 33A-1 in any building or on land supported in whole or in part with public funds or in any building on such land without prior written permission from the chief security officer for such land or building
Commits a Class a misdemeanor.
(b) The chief security officer must grant any reasonable request for permission under paragraph (a).
(Source: P.A. 89-685, eff. 6-1-97.)