Google: Meetup Groups and on the Meetup page, click on "Find a Meetup Group". In the search bar type, Nudist. The new group is called, "Colorado we'd rather be naked. Come join us" If you are only here for sex, you may as well join "Denver Fun in the Sun". Members of that group are not allowed in the new nudist group mentioned.
If you are a "true nudist" join the "rather be naked" group. Because of so few females joining, the group is temporarily restricting males so if you're a single guy, find a women to join with you!!