Cal. Pen. Code § 602.10
Every person who, by physical force and with the intent to prevent attendance or instruction, willfully obstructs or attempts to obstruct any student or teacher seeking to attend or instruct classes at any of the campuses or facilities owned, controlled, or administered by the Regents of the University of California, the Trustees of the California State University, or the governing board of a community college district shall be punished by a fine not exceeding five hundred dollars ($500), by imprisonment in a county jail for a period of not exceeding one year, or by both such fine and imprisonment.
As used in this section, "physical force" includes, but is not limited to, use of one's person, individually or in concert with others, to impede access to, or movement within, or otherwise to obstruct the students and teachers of the classes to which the premises are devoted.
Ca. Pen. Code § 602.10