I am partial to the area up around Red River Gorge/Slade, KY/Natural Bridge. There are tons of trails from mild to wild in the area. Some of the land is public (old gas line trails) and some trails are on private property. Go to Cliffview Resort and they can probably point you in the right direction. They have trails too.
Take I-64 East to the Mountain Parkway.
There used to be a place down around Taylorsville, KY that was on private property. I would lead some yuppies down there with their Land Rovers (Yeah, I had one too.) At last mine was a D-90!
Also, an area called Black Mountain (Harlan County, KY). It is a bona fide off-road park area that also has zip line tours. Looks pretty cool.