Cal. Sts. & High. Code § 27044

The copies of the petition from each county shall be grouped or fastened together and submitted to the county elections official of that county for examination and verification. The county elections official shall have 30 days’ time for the examination of the copies of the petition left with him or her for verification. Within that period of time he or she shall verify each of the signatures on the copies of the petition left with him or her, attach thereto his or her certificate that the copies of the petition have been signed by the requisite number of registered voters and forward the copies of the petition with his or her certificate attached to the Secretary of State.