There are lots of trails in Land between the lakes. I have a buddy there that is very knowledgeable of the area and is a guide for the jeep jamborees. other than that I am still looking for other trails
I second the Land Between the Lakes idea. Back when I had my first Xterra in 2001, I helped form a KY Xterra/Frontier club, but I think it's long gone. We did some wheeling in the Daniel Boone National Forest--Cliffdell Loop?--but from what I just read, it looks like they might have locked that down in the past 5 years. There is a Southeast X club that probably has more info about trails in Tennessee.