All Bay State Conference member schools are public secondary schools and also members of the Massachusetts Interscholastic Athletic Association (MIAA) in District 7 (along with the Hockomock League and the Tri-Valley League in the same regions).

The Wellesley (Carey division member) and Needham (Herget division member) high school football rivalry is the oldest public high school football rivalry in Massachusetts and third oldest high school football rivalry in the United States.

Traditionally played on Thanksgiving morning, the Wellesley High School Raiders and Needham High School Rockets have meet each other 133 times as of 2021 with the first meeting dating back to Thanksgiving morning of 1882 at Morton Field in Wellesley (named West Needham at the time).

[2][3] The 10 members of the Bay State conference consists of Brookline, Framingham, Natick, Newton North and Wellesley in the Carey Division, along with Braintree, Milton, Needham, Walpole and Weymouth in the Herget division.

Depending on the sport Carey and Herget division members will play each other once or twice a year.