Idaho Code § 22-303
The respective boards shall meet at the time and place fixed, and the petitions of each county shall be duly considered and canvassed, and if all, or at least three (3) of them, are found in due order and signed by the requisite number of voters, the said commissioners shall jointly make an order creating the proposed district out of the counties in which the petitioners are found to be sufficient and shall give it a name, and at the same time subdivide the district into as many subdivisions as the commissioners deem necessary, numbering them. The said boards shall at the same time select a board of directors, one (1) from each subdivision, each of whom must reside within the subdivision he represents. Each director shall hold office for the term of four (4) years. Every four (4) years thereafter the board of county commissioners of the counties comprising the fair district shall select a board of directors. In case of a vacancy caused by death, resignation, or otherwise, said vacancy shall be filled for the unexpired term by the board of county commissioners of the county in which the vacancy occurs.
Idaho Code § 22-303