After World War II, there was a push to expand ice hockey among the smaller colleges in Canada. The initial product was the Senior Intercollegiate League, however, that conference lasted for only one season. Eventually, several schools in Ontario and Quebec banded together to form the Ottawa–St. Lawrence Conference.[1] Initially, the league was considered an intermediate conference (roughly equivalent to Division II in the U.S.) and included the second team from McGill. By the early 1960s, however, the conference had grown in strength and prestige and was included in the inaugural CIAU national tournament. In 1971, the three conferences in Ontario and Quebec were realigned according to provincial lines and the OSLC ceased to exist.
Initially, the conference did not have a formal playoff structure to determine the league champion. The OSLC would only hold a playoff if there was a tie for the league champions at the end of the regular season. No playoffs were held in the first 12 years of conference play as no tie ever occurred. In 1962, the conference formalized a postseason for the first time, pitting the top two teams in a single-elimination game for the championship. The tournament was expanded to four teams the following season and remained in place for the duration of the conference.
