Idaho Code § 5-513
Where any suit has been commenced in any court of this state upon any cause of action arising therein against any nonresident, firm or person engaged in the ownership and control of any electric light or water system or other public utility in this state, and where the cause of action arises out of some matter connected with the carrying on and conducting of said utility the summons therein may be served by delivering a copy thereof attached to a copy of the complaint on file to the person in charge or control of said public utility in this state, or to some agent, cashier or clerk in charge of any office of said firm or person in this state used in the carrying on and conducting of such business.
Any judgment rendered in such action shall become a lien upon and bind all the property of such firm or person used in the carrying on and conducting of such electric light or water system or other public utility.
Idaho Code § 5-513