nowhere.
ROCKY HILL had a quad track, but closed it and disolved it into more bike track. the owner, tony, said he will be opening it up for quad practices on select mondays and some other random days as well.
i have heard many people talk about the thomaston dam being legal, but i dont think it is really legal so much as its under the DEP/POLICE radar for the time being.
basically you need to find someone with a lot of private property, or give up and race MX like my brother and i....
NEATVMX