[1] Columbus and Parkview joined the following season from the Little Ten Conference and State Line League, respectively.
[2] The Central Suburban Conference maintained this membership roster for the rest of its eight-year history.
They were replaced by two schools from the Badger Conference (Edgerton and Jefferson) and one from the State Line League (Brodhead).
[4] In 1982, Jefferson and Milton both left the Rock Valley to join the Southern Lakes Conference and were replaced by Beloit Catholic (from the IHSA's Trailblazer Conference)[5] and Big Foot (formerly of the Southern Lakes).
[7] Beloit Catholic left to join the Indian Trails Conference in 1996[8][9] for its last few years before it closed in 2000.