 The Sun Valley High School Vanguards play all interscholastic games in the Ches-Mont League.Until 2007, Sun Valley was part of the Del-Val league, and prior to 2006, had played inter-league games with schools in the Ches-Mont and Southern Chester County Leagues.It became an associate member of the new unified Ches-Mont League starting in the 2007–08 school year, with full membership starting in the 2008–09 year.