Idaho Code § 18-4113
In order to make the application and enforcement of this act uniform throughout the state, it is the intent of the legislature to preempt, to the exclusion of city and county governments, the regulation of the sale, loan, distribution, dissemination, presentation, or exhibition of material or live conduct which is obscene. To that end, it is hereby declared that every city or county ordinance adopted before the effective date of this act which deals with the sale, loan, distribution, dissemination, presentation, or exhibition of material or live conduct which is obscene shall stand abrogated and unenforceable on or after such effective date; and that no city or county government shall have the power to adopt any ordinance relating to the regulation of the sale, loan, distribution, dissemination, presentation, or exhibition of material or live conduct which is obscene on or after such effective date.
Idaho Code § 18-4113