Idaho constitution
Article XVIII
Section 10

The board of
county commissioners shall consist of three (3) members. Their terms of office shall
be as follows: At the general election of 1936 two (2) members shall be elected for
a term of two (2) years and one (1) member for a term of four (4) years; at each
biennial election thereafter one (1) member shall be elected for a term of two (2)
years and one (1) for a term of four (4) years. The legislature shall enact the
necessary measures to put this provision into effect and in so doing shall allot such
four (4) year term to each commissioner’s election district or like subdivision of the
county which may be provided by law, in rotation.