Snow chains or cables add traction when driving through snow and ice. They are usually purchased to match the tire size (diameter and tread width).
From November 1 to April 1 in California, all vehicles are supposed to carry tire chains (or cables) when they enter a chain control area, even if it isn't snowing at the moment. If you don't have them, you can be fined and have to pay charges for damages from an accident. If a law enforcement officer stops you and decides the safest thing to do is to have your vehicle towed out of the snow area, you might also have to pay towing fees.
That all sounds pretty daunting, and you may wonder how you'll be able to see Yosemite National Park or other parts of California if you're planning a visit in winter.
If snow could be predicted with accuracy, it would be easy to know what to do, but the weather changes quickly in the mountains. You could start your trip on a sunny afternoon and end up in a situation where you not only need chains, but you need to put them on in a hurry.
What Are the Chances of Snow?
That's hard to say. In general, it will probably snow sometime during the winter in the mountains. It could snow as early as November. By April, snow season is usually over. Beyond that, things vary by year, and average snowfalls won't help you know what to expect.
If you want to know whether a wet or dry winter is predicted, here's how to find out. Search for the "NOAA Winter Weather Forecast" and look at the maps. It may help to know that El Niño conditions bring warmer ocean temperatures (and more rain and snow) than La Niña.
For planning closer to the time of your trip, use any of your favorite weather apps, but be sure to pick your weather location at the highest elevation you plan to visit.
Forecasts and Road Conditions
For up to date road conditions and closures, you can follow CaltransHQ on Twitter or Facebook or check road conditions on their website or get their app for your mobile device.
These are the levels of snow chain requirements (quoting the Department of Transportation). You'll see them listed on signs like the one above.
Requirement One (R1): Chains, traction devices or snow tires are required on the drive axle of all vehicles except four wheel/ all wheel drive vehicles.
Requirement Two (R2): Chains or traction devices are required on all vehicles except four wheel/ all wheel drive vehicles with snow-tread tires on all four wheels.
(NOTE: Four wheel/all wheel drive vehicles must carry traction devices in chain control areas.)
Requirement Three (R3): Chains or traction devices are required on all vehicles, no exceptions.
Snow Chains and Yosemite National Park
Yosemite is a national park with its own set of rules and regulations about driving and snow. The Yosemite website strongly recommends having chains with you from November through March, but they could be needed as early as September or as late as May. To get up-to-the-minute road conditions in Yosemite, call 209-372-0200. Yosemite Valley is at a lower elevation than the mountain passes. And if you take CA Hwy 140 through Mariposa, you might not encounter snow even if it's falling at higher elevations.
Park regulations require that you MUST carry chains when driving in designated chain control areas, marked by a sign that says, "CHAINS REQUIRED" — even if you are driving a four-wheel-drive vehicle.
Unless it starts snowing, no one is likely to stop you and search your vehicle to see if you have chains with you.
During a snowstorm, park rangers may close the roads to all motorists who don't have chains on their tires. And in the rare instance that you got in without chains and snow starts when you didn't expect it, you might get a traffic ticket, and/or your vehicle could be towed out of the snow area at your expense.
Another way to get into Yosemite when it's snowing and you don't have chains is to park your car at a YARTS (Yosemite Area Rapid Transit) bus stop on CA Hwy 140 outside the chain control area and take the bus into and out of Yosemite (fee required).
Snow Chains and Rental Cars
Few if any car rental companies make snow chains available to renters, but you might find them for rent in Reno, Nevada, which serves the Lake Tahoe ski area. Some car rental companies ban chains or allow them but hold you responsible for any damage they cause, so you will need to check with yours to be sure.
To find out if you have snow tires on your rental, look on the wall of the tire for the letters MS, M/S, M+S, or the words MUD AND SNOW — or an icon of a mountain with a snowflake. If any of those are present, you may be able to drive without chains in R-1 and R-2 conditions.
You can buy chains for your rental at an auto parts store. A set will cost $40 or more. However, most shops do not accept returns (even if they're unused) unless you bought the wrong size.
You can also rent chains in some locations. O'Reilly Auto Parts at 4907 Joe Howard Street in Mariposa rents or sells them - and so do some of the gas stations in town. You may also find them in Coarsegold and Oakhurst. If you buy or rent, ask someone to show you how to put them on. Then try it yourself and take photos of the steps instead of depending on remembering hasty verbal instructions.
Installing and Removing Your Chains
According to CalTrans, you need to install your chains before you reach a checkpoint, which will be about within a mile after passing a "Chains Required" sign. Pull off the road on the right to do that.
If chains are required, the speed limit automatically changes to 25 to 30 miles per hour.
After you pass the End of Chain Control signs, find a safe area to get off the road and remove them.
Chain Installers on the Highways
If you have chains but don't know how to use them, keep cash with you if you travel in areas where they might be needed.
On the busier highways, chain installers (who are called "chain monkeys") spring up during a storm like mushrooms after a big rain. They charge to put chains on for you, and again to take them off. Expect to spend $50 or more if you pay for both services.
Unless you know what you're doing, most people say it's worth the cost to avoid struggling in freezing weather. Some of the installers also sell chains. CalTrans issues them permits, and they have to pass a test that involves untangling a set of chains and putting them on a car in less than five minutes. And they will be wearing a badge. If you use them, be sure to make note of that badge number and get a receipt.
Visiting in Winter
If you're reading about snow chain requirements, you're probably thinking about visiting California in the winter. If you're looking for a short trip away from home, research how to find some places that are perfect for California winter getaways.