[14] The MSL then announced a realignment for the 1965–66 season when Niles West High School and James B. Conant High School were added, with Deerfield, Glenbrook North, Glenbrook South, Niles West, Niles North, and New Trier West comprising one division, and Forest View, Prospect, Wheeling, Maine West, and James Conant comprising the other.

[16] Maine West left the league in 1967 and moved to the Central Suburban.

Glenbard North joined the league in 1968, and Hersey in 1969, closing out the final changes in the conference of the 1960's.

The conference would change again in the early 1970's as Schaumburg was added in 1970, Rolling Meadows in 1971, Buffalo Grove in 1974 and Hoffman Estates in 1975.

Unfortunately, in 1984, based on declining enrollment and high maintenance costs, Arlington High School would close with Forest View seeing the same fate 2 years later.