Idaho Code § 50-234
Except as otherwise provided by law, whenever it has been determined or appears probable that any property of a city has become valuable by reason of veins, lodes, or other deposits of mineral underlying said property, the corporate authority of any city, upon the affirmative vote of one half (1/2) plus one (1) of the members of the full council, shall have the power, by ordinance, to grant a lease in and to such minerals, with the right to mine for and extract the same, provided, that the surface of said property shall be in no wise interfered with or disturbed. Such lease shall provide for such royalties and shall contain such other terms and provisions as said council may deem proper, but in no case shall any such lease be made for a greater period than twenty-five (25) years.
Idaho Code § 50-234