The rally, organised by former NCAA player Sophia Lorey, intensified a public feud between Governor Gavin Newsom's office and the White House over California's transgender sports policy.
California law has allowed students to compete according to gender identity since 2013, and last year's meet drew duelling protests before the Justice Department later sued state agencies over Title IX.
With conflicting state and federal rules, how can schools guarantee both fairness and inclusion in sports for every student?
As the Olympics adopt genetic testing, is biology the new arbiter for who can compete in women's sports?
Beyond the legal battles, what is the human cost for the young athletes caught in this national debate?