Founded in 2000 by Anthony Burdge Heren Istarion: The Northeast Tolkien Society is registered with the Tolkien Society UK.
Heren Istarion is an academic literary group dedicated to celebrating the life and works of Professor J.R.R. Tolkien, C.S. Lewis, and Charles Williams and the promotion and enjoyment of the fantastic, in literature and myth.
The society is quite large and boasts a membership as far south as Tennessee and as far reaching a Sweden. They have a bimonthly journal Parma Nole, published articles, have a nice links page and hosts events around the New York City area to name a few benefits of being a member.
Take a moment and look at Heren Istarion: The Northeast Tolkien Society