You are required to have a valid OHV registration from your home state of residence. You can also purchase a valid IDPR OHV certificate of number sticker in its place. If you wish to operate on Idaho's local jurisdiction roads and don't have a license plate, you must purchase an Idaho restricted vehicle license plate with a valid IDPR OHV certificate of number sticker. You can purchase a certificate of number sticker on the Idaho Department of Parks and Recreation Registration Sticker, Permit and Certificate Sales portal. Idaho restricted vehicle license plates can be purchased at the Idaho Department of Motor Vehicles website.
Check out these Atlanta, ID ATV/OHV resources:
