Idaho Code § 50-1718
Any person who has filed objections to the assessment roll or any other person who feels aggrieved by the decision of the council in confirming the same shall have the right to appeal to the district court of the county in which the municipality may be situated. Such appeal shall be made within thirty (30) days from the date of publication of the ordinance confirming the assessment roll by filing a written notice of appeal with the clerk of the municipality and with the clerk of the district court aforesaid describing the property and objections of the appellant. The appellant shall also provide a bond to the municipality in a sum to be fixed by the court, but not less than two hundred dollars ($200) with sureties to be approved by the court, conditioned to pay all costs to be awarded to the respondent upon such an appeal. After said thirty (30) day appeal period has run, no one shall have any cause or right of action to contest the legality, formality or regularity of said assessments for any reason whatsoever and, thereafter, said assessments and the liens thereon shall be considered valid and incontestable without limitation.
If an appeal is filed within said period, the case shall be docketed by the clerk of said court in the name of the person taking the appeal against the municipality as "an appeal from assessments." Said cause shall then be at issue and have precedence over all civil cases pending in said court, except proceedings under the act relating to eminent domain by cities and actions of forcible entry and detainer. Such appeal shall be tried in said court as in the case of equitable causes except that no pleadings shall be necessary. The judgment of the court shall be either to confirm, modify or annul the assessment insofar as the same affects the property of the appellant, from which judgment an appeal may be taken to the Supreme Court as provided by law. In case the assessment is confirmed, the fees of the clerk of the municipality for copies of the record shall be taxed against the appellant with other costs.
Idaho Code § 50-1718