Idaho Code § 43-102
A petition shall be first presented to the board of county commissioners of the county in which the greatest proportion of the proposed district is situated, signed by the required number of holders of title or evidence of title to the required area of such proposed district, evidenced as above provided, which petition shall set forth and describe, with the degree of certainty required by law in a tax roll, all the lands proposed to be included in said district, and shall state whether it is proposed to purchase irrigation works already in operation or to construct new works, or as the case may be, and shall pray that the same be organized into an irrigation district. The petition, together with all maps, cross sections and papers filed therewith, shall, at all proper hours, be open to public inspection at the office of the clerk of the board of county commissioners between the date of their said filing and the date of the final hearing thereon.
Idaho Code § 43-102