Steep hills would work.
If I don't have an actuall stand to shoot from, I usually climb onto a roof, camper, or something in the 12-15 foot range. One of the biggest things is the size of the platform of the stand you will be hunting from. It's easy to shoot when your on a big surface, but when you're on a 3'x3' (or smaller) platform, 15' up in a tree, it's a little harder to mover around and feel safe. Shoot from both sitting and standing positions.
Don't forget to wear a safety harness and good luck. Illinois is an awesome place for big bucks!
Lien2