Quite a lot. I wouldn't describe all of them as public access, but it's all in who you can get to know, or how well you talk to cops. River Ranch is private property, Lake Wales/Frostproof but almost everyone knows someone who owns property in there. Sebring/Lake Placid has some fun trails. I've heard Lakeland has some, but I haven't seen them. Search for Jeep clubs in Central Florida, I know Lakeland has one. That's where you'll learn the lay of the land, best.