Idaho Code § 40-1511
Immediately following the close of the polls, the votes shall be counted in accordance with the provisions of title 34, Idaho Code. The board of county commissioners shall meet separately at their respective county seats and pursuant to chapter 12, title 34, Idaho Code, canvass the returns within each county. Within fifteen (15) days after the canvass, the commissioners shall meet in joint session at a location as shall be agreed upon by them and compile the total votes cast in their respective counties for or against the proposal to consolidate the highway districts concerned. If the proposal carried in each of the highway districts concerned, the county commissioners in the joint meeting shall make and enter an order declaring the districts consolidated in one (1) highway district of a name or designation as may be ordered by them, and at that time the consolidation shall be effective. The highway districts having been consolidated shall remain in operation, with all legal authority of a highway district, until the newly appointed highway commissioners of the consolidated highway district meet and organize as provided in this chapter.
Idaho Code § 40-1511