Hiking/backpacking in southwest Ohio?

Alright, I'm fairly new to Ohio...and I'm looking for some recommendations.  I think I was spoiled with hiking and backpacking out West and in the Smokies.  What are some good backpacking or hiking locations in Ohio?  For day hikes, I prefer 6-14 mile loops with a few scenic destination points on the way.  For backpacking, I'm mostly interested in options for 1-3 night trips so I can schedule around work.  Thanks!