ATVs that operate on and off-highway are given a street-legal license. You are required to display a California Green Sticker on all off-highway ATVs. The registration fees are $52 per vehicle and it is valid for two years. Green Stickers are only required for ATVs that are unregistered because they are driven off highways. You must purchase a Red Sticker if your ATV is model year 2003 or newer and it fails to meet emission standards. You can apply for Green and Red Stickers at the California Department of Motor Vehicles.
Check out these Yuba City, CA ATV/OHV resources: