California Code, Streets and Highways Code - SHC § 27104

The Secretary of State shall attach the protests which he receives from each county to the petition filed from that particular county, and forward the petition with the protests attached to the superior court of that county.  The superior court in each county shall have jurisdiction to hear and determine the protests so received.  The clerk of the court shall set the protests for hearing, and give notice thereof in writing to the protestants, and to their attorneys if they have any, at least 10 days before the date set for the hearing.