Is Metal Detecting allowed in Illinois State Parks: YES, by permit only.
A link to the Illinois Department of Natural Resources on Metal Detecting can be found HERE:
It is Unlawful for :
For any person to collect or take artifacts and/or mutilate, destroy, deface or excavate anyarchaeological site except as provided by permit according to 17 Ill. Adm. Code 370. http://www.dnr.illinois.gov/adrules/documents/17-370.pdf
There is also an FAQ site found HERE:
Q. Where can I use my metal detector on public lands?
A. Not all sites allow metal detecting to protect significant cultural or natural resources. Those that do, require permits that can be obtained at the park office. If there is a specific park that you want to metal detect at, please call the site first.
FMDAC Disclaimer: FMDAC assumes no responsibility for any person who knowingly or accidentally violates any state park regulation. Although FMDAC will try to keep this information current we cannot anticipate how each regulation will be interpreted by a specific park department, park employee or other government employee. It is the sole responsibility of each individual to know and obey the regulations of the park or area they are visiting and or metal detecting.