There used to be, but I've been gone from there for years now. Every time I've gone back, more stuff is developed.
Lehigh/Alva/North Cape might help narrow the search. FTMyersTRD is around here somewhere, you might want to get ahold of him (I've seen him put up some pictures from rides and such before). A huge place near you is:
Big Cypress National Park ORV Bear Island, which you might want to check out too.