I suggest contacting the school to learn more about yearbooks for previous years. They may connect you with a student association or PTA representative who can assist you with getting a copy of the yearbook. If you don't have the school's telephone number handy, and if located in the U.S., you may use SchoolFinder to research the school's contact info (link to SchoolFinder below).
Alternatively, you may be able to reconnect with middle school classmates via online social networks. I have seen many yearbook photos shared on Facebook, for instance.
Good luck in your search, and thank you for asking!