Idaho Code § 61-333A
In the event an area hereafter shall be included as a result of incorporation or annexation within the boundaries of a city, town or village, any public utility and any cooperative association organized for the purpose of furnishing electric service to its members or consumers only, furnishing electric service or operating electric facilities in such area prior to such inclusion, shall, unless the municipality acquire such facilities pursuant to section 61-333B, Idaho Code, and subject to the provisions of sections 61-332B and 61-332C, Idaho Code, have the right to continue and extend the furnishing of electric services in such area, and to utilize public streets, alleys and thoroughfares, or such portion of such annexed area as is designated on the recorded plat for the installation of utilities, for such purpose. Such public utility or cooperative association shall comply with all lawful and reasonable safety requirements and the laws of the state of Idaho and nondiscriminatory ordinances of the city, town or village, as to the manner of constructing and maintaining electrical facilities therein.
Idaho Code § 61-333A