The high schools of the Big Northern Conference are located in the following counties: Boone, DeKalb, LaSalle, Lee, Ogle, Whiteside, and Winnebago.
Of the remaining football teams from each conference, Pecatonica played in a co-op with Winnebago, Polo and Mt.
In 1995, the Big Eight and Mid Northern merged for all sports, with Ottawa Marquette remaining the only football-only member.
Pecatonica (who ended their co-op with Winnebago in football) and Polo joined the Upstate Illini in 1995, while Mt.
In 2018, Rockford Christian moved to the Northeastern Athletic Conference in football while remaining in the BNC for all other sports.
Having 10 teams in football made it possible for the BNC to have a full conference schedule, as there are 9 games in the regular season.
Ottawa Marquette was independent in all non-football sports during its entire time associated with the BNC.