Idaho Code § 27-103

When the boundaries of a proposed cemetery maintenance district lie in two (2) or more counties, each county shall act separately in the election and organization of that part of the proposed cemetery maintenance district contained in its county: Provided that the boards of county commissioners of each county so joining, shall meet together upon the presentation of the petition to their respective bodies, asking for such proposed district, and provide for uniform proceedings in each county. When two (2) counties join in a cemetery maintenance district, the county having the larger population within the district, shall appoint two (2) of the three (3) cemetery maintenance commissioners and the county having the smaller population within the district, one (1) commissioner. When three (3) counties join in such district, each county shall appoint one (1) commissioner; when more than three (3) counties join in such district, the three (3) counties having the largest population shall each appoint one (1) commissioner.