Sam and Dean introduce themselves as Fathers Penn and De Niro. This is a reference to the movie We're No Angels (1989) starring Sean Penn and Robert De Niro.
Sam and Dean's fake identities are Jim Morrison and Ray Manzarek, respectively the singer and keyboard player for The Doors. It is unusual for the Winchesters to provide full names of real people, so this may be a reflection on the "off the grid" nature of the people they are investigating.
William MacDonald, who plays Abraham Peterson, also played the sheriff in S05E08 "Changing Channels".
This episode marks the 245th episode of this series as well as for its 2 main leads: Jensen Ackles and Jared Padalecki.
Mason City, Iowa, was the hometown of Meredith Willson, and the inspiration of the town, River City, in his hit play and movie, "Music Man".