SDCL § 31-13-54: Contracts and assessments not invalidated by defects--Supervisors' determination conclusive.

No contract made or assessment levied for any such improvement shall be void by reason of any defect or irregularity in the resolution or notice or in the publication thereof. The determination of the board of supervisors as to the sufficiency or insufficiency of protests thereto shall be conclusive unless such determination is unreasonably and arbitrarily or fraudulently made.