Defines "landlocked property" as real property that has been shut off from all public highways as a result of the vacation of one or more public highways. Provides that if an action of the state, or an agency or political subdivision of the state, causes real property to become landlocked property, the county assessor of the county in which the landlocked property is located must assess the value of the landlocked property at zero for as long as the property qualifies as landlocked property if the property owner files an affidavit stating that the property does not have access to any public highway.