It shares some resources with the all-boys De La Salle High School, which is across a side-street that separates them.

De La Salle High School was founded by the Christian Brothers.

[1] At that time, Carondelet was the only Catholic high school for girls in Contra Costa County.

In September 1969, Carondelet established a cooperative academic program with De La Salle High School,[2] the all-boys Roman Catholic campus located across the street.

[1] Thus, Carondelet expanded their academics by allowing juniors and seniors from both schools to attend selected classes from either campus.