Upon a closer look, the USN&WP stated that Dublin HS had 497 students. I remembered it to hold at least 1500 students back in the day and I know its attendance area has now turned into an overcrowded megalopolis. Upon perusing its Wiki page:
I learned it now has a “school within a school” (similar to SDHS in SD) called the “Engineering and Design Academy.” Perhaps THIS is the “school” which won the USN&WP award and where 100% of students took and passed AP classes! I also learned it won a similar award in 2010.
Acc to its wiki page, DHS appears to be currently in the process of turning into a mid-century monstrosity (with $120M from voter-approved “Prop C” funds), is slated to be finished this year to hold 2500 students!
I think the individual school info put out by USN&WP is a bit misleading as to CA schools, perhaps thru no fault of their own. These awards were such a large project and perhaps they depended upon the schools to report the info to them and the magazine likely did not really understand how each school is structured.