Idaho Code § 23-604: Minors — Purchase, consumption or possession prohibited.

Any person under twenty-one (21) years of age who shall purchase, attempt to purchase, or otherwise consume or possess any alcohol beverage, including any distilled spirits, beer or wine, shall be guilty of an infraction upon a first violation and shall be guilty of a misdemeanor upon a subsequent conviction and shall be punished according to the schedule set out in section 18-1502, Idaho Code.