Actually, here's a website that'll tell you everything you need to know, from local (Sonoma County) activists who picket and try to infiltrate the Bohemian Grove every year. Cool site:
http://www.sonomacountyfreepress.com.../bohoindx.html
Here's also a link to a pretty good article in the SF Chronicle about elite SF men's clubs, including the Bohemian Club. Talks a lot about what goes on in the grove.