I had not checked into State parks as of yet, Apparently it's possible to get permission to hunt dry areas....although it seems dependent on one person giving the permission.
I got this off of the Ohio State Parks website...
Q. Can I use a metal detector?
A.
Use of metal detectors is allowed on the sandy portion of the beach area at any of our state park beaches. Written permission must be obtained from the park manager at the park of your choice to use a metal detector in any other park area.
Either way Josh, you can hunt the metro parks with a free, easily obtainable permit. Although it seems very unlikely you will ever be requested to show it, it's good idea to get one. Just call and pick it up the next day
Just to clear things up a little, The Metro parks and State parks are not the same thing. Oh... and I am speaking of "Cleveland Metro park system"... .you didn't say exactly where you're coming to visit.