I don't know of any trail groups. I just wheel with any one who also wheels whenever we can. My last 'Yota buddy sold his truck, and I don't wheel with domestics... I hate towing people out in the bush.
My buddy Dan has a 4Runner that we have done some good modding too, it used to be my Dad's truck. He is my new wheeling buddy of late, but I wanna get some more FJ's to come out with us.