California Code, Streets and Highways Code - SHC § 5321

All real property acquired by the State of California or any department thereof is property subject to assessment in proceedings conducted under this division, except real property which is acquired prior to the filing in the office of the county recorder of a copy of the map of the assessment district pursuant to Section 3111 and which is located within the right-of-way of a state highway or proposed state highway. For the purposes of this section, property shall be deemed to have been acquired upon the vesting of title, or the filing of a condemnation action, whichever occurs first. The local agency shall notify the Department ofTransportation of any proceedings or hearings to be held relative to the establishment of a map of the assessment district pursuant to Section 3111.