Snow & ice can exist on park roads. You are required by federal law to carry tire chains in your vehicle if entering a designated chain control area, even if your vehicle is equipped with snow tires and/or four-wheel-drive. Chains can become mandatory on any park road at anytime.
When chain controls are established, signs will be posted along the road indicating the type of requirement. There are three levels of chain requirements: R1, R2, and R3.
(R1): Chains or snow tires are required on the drive axle of all vehicles except four wheel/ all wheel drive vehicles.
(R2): Chains are required on all vehicles except four wheel/ all wheel drive vehicles with snow-tread tires on all four wheels.
(R3): Chains are required on all vehicles, no exceptions. Including those with four wheel/ all wheel drive
Chains should be the correct size for your tires. Chains must be installed on drive wheels, so you need to know if your vehicle has front or rear wheel drive. For cars with four wheel or all wheel drive chains must be on one axel. Cable-type chains are acceptable, but they may not provide as much traction as traditional chains.
Control areas can change rapidly from place to place because of changing weather and road conditions. You must put on chains when highway signs indicate chains are required. You can be cited and fined by the California Highway Patrol if you don't.
For current road information inside Yosemite call 209-372-0200. Select 1 and then 1 again.
For current road information outside of Yosemite National Park, call CALTRANS at: 1-800-427-7623 (1-800-GAS-ROAD).
Additional Information:
- Mud and Snow tires are typically designated with a "M+S" on the side of the tire, and must have a minimum tread depth of 6/32 of an inch to be legal.
- Tire traction devices (chains) can be link chain, cable chains and/or spider straps
- Studded snow tires may be used if the tires are also rated as snow tires, if not, the tires must be chained up as Studs do not replace chains.
- Any vehicle with a gross vehicle weight of 10,000 pounds must chain up. (Typically this applies to large vans and up.)
- All vehicles, including those with 4-wheel drive with snow tires that are towing trailers must have chains on one drive axle of the vehicle
- If the trailer has brakes, it must also have chains on one axle.
