[7] Allendale and Upper Saddle River switched to Northern Highlands Regional High School when it opened in 1965.

Delays in starting the work meant that the initial set of classrooms would not be available until November 1958, with completion of the 1,200-student capacity facility due for February 1959.

[17] In May 1963, voters in Allendale and Upper Saddle River approved a referendum to create Northern Highlands Regional High School, with the expenditure of $3.65 million to build a facility on a 40-acre site, with plans to complete the building in time to start classes in September 1965.

[22] The Mahwah High School Thunderbirds[2] compete in the Big North Conference, which is comprised of public and private high schools in Bergen and Passaic counties and was established following a reorganization of sports leagues in Northern New Jersey by the New Jersey State Interscholastic Athletic Association (NJSIAA).

[29] Since the playoff system was introduced in 1974, the team has won the NJSIAA North I Group I state sectional championship in 1978, 1979, 1981, 2015 and 2016.

[30] The 1978 team finished the season with a 10-1 record after a 48-20 win against Park Ridge High School in the North I Group I state sectional championship game.

[31] The team won the 1979 North I Group I sectional title with a 49-16 win against Pompton Lakes High School in the finals.

[32] In 1981, the team finished the season with a 9-1-1 record after winning the North I Group I state sectional title by defeating Park Ridge High School by a score of 21-11 in the championship game.

[36] The girls' basketball team won the Group II state title in 1993, defeating Delran High School by a score of 34-27 in the tournament final played at Monmouth College.

[40] The 1985 team finished the season with a 15-3-3 record after winning the Group I title with a 4-0 victory against Maple Shade in the championship game played at Mercer County Park.

[42] The team had made it to the 2009 NJSIAA Group II State Finals, before losing 2-1 in overtime to Haddonfield Memorial High School.

[43] The girls tennis team won the Group I state championship in 1985, defeating Haddonfield Memorial High School in the tournament final.

[44] The team won the 1985 title with a 4-1 win against Metuchen High School in the semifinals and a 5-0 victory in the finals against Haddonfield.