With the USFS having engaged in the systematic closure of most of the OHV areas in or near North Georgia (Tellico-2009, Anderson Creek-2005, Bell Mountain - 2005, Rich Mountain-2004) or the re-classification of others in the areas for ATV but not 4x4 use, there are fewer places to go to off-road with our vehicles in GA on National Forest land. Because of this, there has been an increase in the number of OR Parks in GA.
I have no experience with any of these, but here are the ones that I have found:
West Georgia OffRoad Park (Opening soon???):
http://www.westgaoffroadpark.com/ (homepage URL dead as of 08/01/2009)
East Coast Off-Road Park
http://www.ecc-orp.com/
Durhamtown Plantation Offroad Park
http://www.durhamtown.com/
River Rock Off Road Park
http://www.riverrockorv.com/