(a) The validity of an assessment may not be contested by a person who did not file with the municipal clerk a written objection to the assessment roll before its confirmation. (b) The decision of the governing body on an objection may be appealed to the superior court within 30 days after the date of confirmation of the assessment roll. If no objection is filed or appeal taken within that time, the assessment procedure is considered valid in all respects.
Alaska Legal Code