I would take a guess that if someone wanted to make such a park based on the film or books that the rights that Saul Zaentz owns just may cover it. However, anytime you get into this type of thing its all in the contract and that has never been made public.
Funny thing is that if Disney had kept to their plans to make the films this just might be something that achieved reality. Not that I would trade the excellence of PJ's version for it...
