California Code, Streets and Highways Code - SHC § 26061

Notice of the election shall be given by posting a copy of the order for three successive weeks prior to the election, in three public places within the proposed district, and by publication of a copy of the order at least once a week for three successive weeks prior to the election in a newspaper published in the proposed district, if there be one, and if not, in a newspaper published at the county seat of the county in which the district is located.