Idaho Code § 57-501
In all cases where the state or any county, city, village, school district, highway district, good roads district, irrigation district or drainage district, has issued and sold, or may hereafter issue and sell, its bonds and the same are outstanding and unpaid and which may under the laws of this state be refunded and called for payment, the state, county, school district, city, village, highway district, good roads district, irrigation district or drainage district having issued and sold said bonds, may refund the issue and sell refunding bonds in the manner provided by the law for the purpose of calling and paying said outstanding bonds, and may execute, sell and deliver said refunding bonds and receive the money therefor prior to or subsequent to calling for payment or paying and canceling the bonds so refunded, and such refunding bonds when so sold and delivered shall be legal and binding obligations of the state, county, school district, city, village, highway district, good roads district, irrigation district or drainage district issuing and selling the same.
Idaho Code § 57-501