From their website:
What do we do?
We publish a newsletter ten times a year. We maintain a family friendly presence at Black's Beach. We maintain a bulletin board at Black's Beach. We post our newsletter there and leave space for others to post Naturist related events. We organize trash pickups at Black's Beach, sometimes with park rangers. We donate materials and service to Black's Beach Diggers. We facilitate the use of Black's Beach for other Naturist groups by providing a hot grill, extra umbrellas, and beach toys like Frisbees, body boards and sand castle molds. We organize a few events, but mostly leave it up to people to decide how to have fun at the beach.
Why do we do it?
Clothing optional recreation requires constant defense, because people often misunderstand and try to outlaw it. Black's is not a perfect beach, but we try to make it better. We like our beach to be litter free. We like to be able to reach a clothing optional environment without excessive risk to our lives.
What don't we do?
We don't engage in public sex, nor do we encourage public sex. We don't police the entire beach, but we often speak up when people get vulgar. We don't sponsor many activities because people at Black's already know what they want to do and don't need us trying to organize fun.
How do I join?
Membership in Black's Beach Bares is not based on dues, nor is there a list of members. It's based on behavior and participation. If you can behave the way polite society expects, then we will tolerate your presence. If you can be a part of our activities or conversations, then we will welcome you.
Anza Borrego Desert
Cuyamaca State Park