I think that word organization has negative connotation. Geocaching is a cool tech game, and (in my opinion) an "organization" would take the fun out of it. That doesn't mean that set up a local informal geocaching group, they are fun. You can put together small events to get to know local cachers, the gathering may grow, more organized with time and eventually you may get your organization. I would suggests to start small and go from there. Good Luck