Mike Burnham, shown in 2022, plans to retire at the end of June after seven years as executive director of the Maine Principals’ Association’s interscholastic division. (Andy Molloy/Staff Photographer)Mike Burnham, the executive director for interscholastic sports at the Maine Principals’ Association, has announced his retirement, effective at the end of the school year. Assistant executive director Mike Bisson will take over as the executive director on July 1. During Burnham’s time as assistant executive director and executive director, the MPA ushered in the inclusion of Unified sports, eight-player football and soccer and girls hockey. “And my first year (as assistant director) was the first year of girls ice hockey.