To know for sure if cowbells are allowed at a specific California high school game, you should:
* Check the school's website: Many schools post their spectator guidelines or codes of conduct online.
* Contact the school directly: Call the athletic department or principal's office.
* Check with the school district: The district may have overarching policies regarding noise at events.
Essentially, the legality depends on the specific school's rules, not a blanket state law.