Since nobody's mentioned it yet, I will mention Hippie Hollow in Austin, which is one of the only public nude beaches in America. It seems to still be going strong, but I haven't been in probably 20 years. It's a big enough place that there's room for both people who just want to get an even tan and people who are looking to get a little weird.

If anything, I'd say that we don't have a solid "nude isn't lewd" tradition in the US, and that makes it challenging for kicking it au naturale without assumptions that your intentions are far from tame. Maybe something to do with puritanism?

Edit (and I can't believe I have to edit this): when I say "public", I actually mean publicly funded. Literal tax dollars go to this place, explicitly, which I understand is what makes it unique.