During the episode in which The Gang is "interviewing" other teens to choose a new friend and member of their group, they have a private discussion about one girl's highlights. Among those listed is the fact that " . . . her dad works at Six Flags", an obvious reference to Six Flags Great America theme park in nearby(?)Gurnee, Illinois. However, in the '70's the park was owned by Marriott's. It was sold and became a Six Flags park in 1984.

The Six Flags slip-up was repeated in at least one other episode.