I love St. Simons. Can't say there's much in the way of off-roading, definately no Mtn biking. Take your bike anyway. You can ride almost anywhere via side streets and bike paths. I think there is a WMA north of Brunswick off the Midway exit. I can't remember the name of the place, but it's an old WWII airfield. Be sure to eat at the Buccaneer Restaurant up that way, it's about as true of an old cracker south seafood restaurant as you'll ever find. You have to ring a doorbell so they can look out and decide whether to let you in. And they do do let black folks in, just not scumbags, most of whom are white. Jeckyl Island which is the one to the south has a bike path all around it and a great historical district. Next time we go, I plan to have a road bike.