California Code, Business and Professions Code - BPC § 25620

(a) Any person possessing any can, bottle, or other receptacle containing any alcoholic beverage that has been opened, or a seal broken, or the contents of which have been partially removed, in any city, county, or city and county owned park or other city, county, or city and county owned public place, or any recreation and park district, or any regional park or open-space district shall be guilty of an infraction if the city, county, or city and county has enacted an ordinance that prohibits the possession of those containers in those areas or the consumption of alcoholic beverages in those areas.

(b) This section does not apply where the possession is within premises located in a park or other public place for which a license has been issued pursuant to this division.

(c) This section does not apply when an individual is in possession of an alcoholic beverage container for the purpose of recycling or other related activity.