Arroyo Seco Junior High School held a double graduation at the end of the 1974-75 school year as both the 8th and 9th grades moved up to become the first students at Saugus High School, which opened in September 1975 with the 9th and 10th grades.

Purists will note that the yearbook says Arroyo Seco is in Saugus. The argument can be made that it's technically in Valencia, but it was then and has remained the feeder school for Saugus High. Which is in Saugus.