13th = JORBAFest
The 13th is JORBAfest. Link
It is being held at Stephens State Park which is on the south side of 80 from Allamuchy. There will be plenty of group rides associated with the day. Check out the link above, this thread
or JORBAs wiki
Also, keep an eye open, there are frequently group rides at Mahlon Dickerson, Kittatinny Valley, Allamuchy, Deer Park, Stephens, Waywayanda, Jungle Habitat and Ringwood in the area.