Bear, you will need the DNR stickers, kinda like watercraft, except its 30 dollars for three years. There are actually two State areas now, one is Interlake and the other is Redbird, both in the Southern part of the State. Interlake is still free, but Redbird is 10 bucks, this goes towards trail maintenance, and up keep. If your into seeing what Indiana has to offer or would like to get involved in helping with getting new trails opened, visit these two sites:
www.discoverindianaridingtrails.com
www.atvwithcutter.com (go into forums)

Let me know if you can make the ride, there will be some great OHV people there to ride with.