You can join the Club for only $20/year (U.S. Memberships) and $25/year (Foreign Memberships) [Ed: $25/Year for everyone (US or foreign) as of 2017]. For that you get four quarterly newsletters a year. You can join with Paypal and your credit card. Just visit the membership application page.
The owners of Charles Mound, Illinois, require that you are a Club member (in order to eliminate problems caused by non-club members who abuse their property). [Ed: Not true as of 2008. Anyone can summit Charles Mound – but ONLY on specific open access dates].