If any depositing unit as defined in this chapter, or any part thereof, is located or deemed to be located in two (2) or more counties of the state, then the county auditor of whichever one of such counties as is from time to time designated by the supervising board of such depositing unit, and he alone, shall have, exercise and be vested with all the rights, powers and duties with respect to such depositing unit and the whole thereof, as a county auditor has or exercises under the provisions of this chapter with respect to depositing units located entirely in his own county.
Idaho Code § 57-109