not much activity in this forum, so i'll try to help out a bit:
close by is rend lake and wayne fitzgerald state park... never been, but it's close...
about 1.5-2 hours south is the shawnee national forest and several state parks nestled within... good sights to check out are giant city state park, bald knob cross, fern clyffe st park and garden of the gods.... not sure how much access you'll have with a wheel chair, but it's worth doing a little research... been in this area countless times---very beautiful part of illinois...
about 2 hours north, along I-57 are the amish/mennonite towns of arthur and arcola... i've been thru there once, but they're not as impressive as other areas out east.....