[6] The school opened in phases starting in October 1962 as sections of the facility were completed and had 620 students in its inaugural year, including 200 from Riverdale, who attended as part of a sending/receiving relationship.

[24][25] The girls' soccer team won the Group I state championship in 2006 (against Metuchen High School in the final game of the tournament) and in 2014 (vs.

[26] In 2006, the team won the North I Group I tournament, defeating Cresskill High School by a score of 5-0 in the final game.

[citation needed] In 2008, the girls soccer team became the first Group II school to win the Morris County Tournament championship.

[30] In 2014, the girls soccer team defeated Park Ridge High School to win the North I, Group I sectional title.

[33] The girls' basketball team won the 2007 North I Group I sectional championship with a 48-37 win over Butler High School.

[36] In 2008, the Kinnelon ice hockey team beat the Jefferson Township High School Falcons at the Prudential Center to win the Public B state tournament.

[39] In 2009, the boys' lacrosse team finished the season with a 16-6 record after winning the Group I state championship, defeating Chatham High School by a score of 11-9 in the title game.

[45] The girls tennis team won the Group I state championship in 2017, defeating Mountain Lakes High School by 4-1 in the tournament final.