The word "interscholastic" is an adjective.
California Interscholastic Federation
Interscholastic was created in 1999.
University Interscholastic League was created in 1910.
Arizona Interscholastic Association was created in 1925.
California Interscholastic Federation was created in 1914.
Interscholastic League of Honolulu was created in 1909.
Interscholastic Hockey League was created in 1998.
Sussex County Interscholastic League was created in 1976.
Rhode Island Interscholastic League was created in 1932.
Washington Interscholastic Activities Association was created in 1920.
Nevada Interscholastic Activities Association was created in 1922.