Idaho Code § 31-1404
When such petition is presented to the board of county commissioners and filed in the office of the clerk of such board, the said board shall set a time for a hearing upon such petition, which time shall not be less than four (4) nor more than six (6) weeks, from the date of the presentation and filing of such petition. A notice of the time of such hearing shall be published by said board, once each week for three (3) successive weeks previous to the time set for such hearing, in a newspaper published within each county in which said district is to be situated. Said notice shall state that a fire protection district is proposed to be organized, giving the proposed boundaries thereof, and that any taxpayer within the proposed boundaries of such proposed district may on the date fixed for such hearing appear and offer any testimony pertaining to the organization of such district, the proposed boundaries thereof or the including or excluding of any real property therein or therefrom. After hearing and considering any and all testimony, if any such be interposed, the county commissioners shall thereupon make an order thereon either denying such petition or granting the same, with or without modification, and shall accordingly fix the boundaries of such proposed district in any order granting such petition. The boundaries so fixed shall be the boundaries of said district after its organization be completed as provided by this chapter, and a map showing the boundaries of such proposed district as finally fixed and determined by the board of county commissioners shall be prepared and filed in the office of the clerk of said board.
If the district is to be situated in two (2) or more counties, each board of county commissioners shall coordinate the hearing date and the publications of notice so that only one (1) hearing need be held. Unless otherwise agreed to by each board of county commissioners involved, the hearing shall be held in the county with the largest area to be included within the district, and the boards of county commissioners are hereby specifically authorized to act in a joint manner for such purposes.
Idaho Code § 31-1404