Idaho Code § 40-1903: County zoning ordinances.

It is the intention of the legislature to occupy the whole field of regulation by this chapter, except that nothing in this chapter prohibits enforcement of any or all of its provisions by persons designated to act by appropriate ordinances duly adopted by any county of this state, nor does this chapter prohibit the passage by any county of reasonable land use or zoning regulations affecting the placing of advertising displays or the placement and operation of junkyards, in accordance with the provisions of chapter 65, title 67, Idaho Code.