Northwest Jersey Athletic Conference  The Northwest Jersey Athletic Conference (NJAC) is a sports league that includes public and private high schools from Morris County, Sussex County and Warren County, New Jersey, that operates under the auspices of the New Jersey State Interscholastic Athletic Association. The conference was formed in 2009 by the NJSIAA as part of a major statewide reorganization of athletic leagues and included schools that had previously been members of the Sussex County Interscholastic League as well as Morris County schools that had been part of the Colonial Hills Conference, Iron Hills Conference, and the Northern Hills Conference. Two northern Warren County schools opted to leave the Skyland Conference to join the NJAC; Hackettstown joined when the conference formed, while North Warren officially becomes a member in the fall of 2012. Members of the Northwest Jersey Athletic Conference include: