Formed in 1960 as the Big Eight Conference, the conference became the Big Nine Conference in 1962 with the addition of
Mt. Morris High School. Ainsworth High School left in 1968, and Mt. Morris left in 1972.
Powers Catholic High School joined in 1974. In 1976, Carman High School and
Swartz Creek High School were added from the
Flint Metro League, giving the conference its peak membership of 10. Due to the collegiate
Big Ten Conference, the conference's name remained the Big Nine Conference. Membership in the Big Nine remained stable for the next 21 years, with only the newly merged
Carman-Ainsworth taking Carman's place in the conference in 1986. Owosso High School left in 1997 for the Mid-Michigan Athletic Conference - A. Beecher left the league after the 2002 season. In 2006, the entire Big Nine Conference and Flint Northwestern applied for membership in the Flint Metro League to encourage discussion on a merger. As a result of that and Kearsley's interest back in 2005–2006, a membership invitation was extended to Kearsley. In 2007, Owosso left for the
Capital Area Activities Conference - Red. In August 2011, the remaining Big Nine members applied together to join the
Saginaw Valley League and were accepted to join starting in the 2012–2013 school year, forming Saginaw Valley's southern division with the other Flint City District High Schools. ==Membership==