It is illegal to wear a mask in public with the intent to conceal your identity.

The Law Explained

Originally passed in the mid-20th century, this law was intended to curb the activities of the Ku Klux Klan and other dangerous secret societies. By making it a crime to obscure one's face in public spaces, lawmakers hoped to deter organized intimidation and mob violence. It remains on the books today, though it includes exemptions for Halloween and medical reasons.