The Schomberg Cougars were founded in 1969 as a member of the Eastern Junior D League, but moved to the South-Central Junior D Hockey League in 1971. There had been a Junior team from the Metro Junior B Hockey League playing for a few years in the early 1960s.
In 1973, the Cougars and their league were promoted, as the league became the Central Ontario Junior C Hockey League. Three seasons later, the league became the Mid-Ontario Junior C Hockey League.
Not a lot is known about the Mid-Ontario League other than what teams played in it. Their competition revolved the Orangeville Crushers and Bradford Bulls, but it is unknown if the Cougars won any league titles.
In 1994, the Mid-Ontario Junior C Hockey League merged with the Georgian Bay Junior C Hockey League. The Cougars continued as members, but the league was dominated by teams like the Stayner Siskins and the Fergus Devils.
The year-to-year play of the Cougars could be considered as inconsistent, but in 2002-03 the Cougars finished the regular season in a three-way tie for second place.They went on to win their first and only Georgian Mid-Ontario Junior C championship that year, after defeating Erin in seven games in the semi finals, as well as Stayner (frist place team) in six games. That year the Cougars had the three top scorers in the league. The Cougars did not manage to reach the Clarence Schmalz Cup finals after losing in four straight games to the Hanover Barons of the Western Ontario Junior C Hockey League.
The 2005-06 season saw the Cougars finish in fifth place in the Georgian Mid-Ontario League. They entered the playoffs against the fourth seeded Erin Shamrocks. The Shamrocks made quick work of the Cougars, finishing the series four games to one.
The 2006-07 season had the Cougars finish in sixth place. In the league quarter-final, the Cougars faced the Alliston Hornets, who swept the Cougars four games to none.