Idahoans have to remove their studded snow tires before May 1 – that’s Thursday. Some of our neighboring states, however, required studded tires to be removed a month ago. In Utah, Oregon and Washington, studded tires had to be off by March 31st. Nevada matches Idaho’s rule with an April 30 final day. Montana lets the studded tires go a month longer – until May 31st – and in Wyoming studded tires are legal all year ‘round.