Winter Driving & Chain Controls

Will I need chains in Yosemite?

Ah. The perennial question. I’m coming in {Winter Month X} will I need chains?

The reason this is so hard to figure out is that there isn’t an easy yes or no answer. Chain requirements depend entirely on the road and weather conditions. February with no snow? No chains needed. Early October with a freak storm that drops 2 feet of snow? The rangers are going to want you to have some extra traction in the snow. Better have chains.

So, the only way to know for sure if you’ll need chains is to check the weather right before your visit, and each day before you head out. But, there are a few general rules of thumb to help you plan for your visit.

Generally Speaking

  • If you’re planning a trip between October and April you’ll want to pay extra close attention to weather conditions. (The resources/references we use are listed below.) These are the months that we are most likely to get significant snow.
  •  Elevation matters. When a storm rolls in, lower elevations in the park are more likely to get rain instead of snow. So, you may be fine driving without chains at 4000 feet in Yosemite Valley, but need chains to go up to the ski area at 7000 feet.
    • Hwy 140 is also called the “All-Weather Highway” because it is the lowest road into Yosemite Valley and therefore is the most likely to be snow-free or have lower chain restrictions on it. When driving in the winter, it’s often faster to take this route even if the mileage is a bit longer.
    • The entrance to our neighborhood, Yosemite West, is at 6000 feet. Being so close to the ski area, we often have some sort of chain requirement during the winter.
  • In over a decade of living here year-round, we’ve only had to put chains on our AWD/4WD vehicles a handful of times. If you have or can rent an AWD/FWD car you greatly reduce the chance that you’ll need to put chains on. (But you still need to carry some, just in case.)

Chain Control Levels

Just because you’re entering a chain control area doesn’t necessarily mean that you will need to put chains on your vehicle.

The purpose of the chain control requirement is to keep everyone on the road, so depending on the conditions and the kind of vehicle you’re driving you may not need to put on chains, even if you enter a chain control area. There are special rules for buses and commercial vehicles, but for most passenger vehicles the guidelines can be summarized as follows:

R0 – Nobody needs to have chains on their vehicle, but everyone should have them in their car in case the weather changes.
R1 – The roads are slippery, but most people will be fine as long as they have mud and snow rated tires on their car with some decent tread.

  • Mud and snow rated tires will have an “M+S” on the side. This is not the same thing as a “snow tire” in the Midwest or Northeast where Tom and I learned to drive, and comes standard on most rental cars.
  • The amount of traction your tires have makes a big difference. If your car has road slicks, bald or significantly worn tires, put chains on. If you have less than 6/32 inches of tread depth you’ll need to put chains on.

R2 – 2WD cars need to put chains on. AWD or 4WD vehicles are still fine without chains if they have good tires (M+S and more than 6/32 inch tread depth). A few notes on R2…

  • It is common to have R2 conditions on the road up to the ski area.
  • Everyone has 4-wheel brakes. Having 4WD doesn’t mean you can drive fast, corner hard, and stop on a dime in the snow. You still need to drive cautiously. See more tips on that below too.
  • Pro-tip: Put your chains on at the pull-out by the chain control sign even if the road doesn’t look very snowy. The reason the rangers have changed that sign is that it will GET snowy before the next place you can safely pull off the road to put your chains on. The last thing you want to do is crawl around on the ground in the middle of the road with cars skidding by (on the slippery road) because you didn’t put chains on when there was a safe wide place to do that.

R3 – Everyone needs to have chains on. Santa would put chains on. Frosty the Snowman needs chains. Have them, and put them on.

The rangers rarely use this chain control level, but when they do, it’s serious. One scenario would be if it were snowing all day, and the people at the ski area need to get home. It’s the end of the day, so there are a lot of cars all leaving at once, and if one car goes off the road it impacts a lot of people.

  • Pro-tip: If there is a storm forecast for the day there will be a ranger check-point on the road to the ski area making sure everyone has chains. Do NOT lie to the ranger and say you have chains when you don’t. A ranger that has been lied to tends to be extremely unsympathetic when the road is R3 and you’re stuck.

Winter Driving – How to Drive in the Snow

  • Not too fast: When the roads are slippery, you won’t be able to stop quickly. This makes it incredibly important to stay alert and keep your speed down.
  • Also not too slow: The winding mountain roads in Yosemite have banked corners. This is great in the summer, but if you’re going too slowly on icy roads, you can actually slide sideways down the bank. I’ve seen a car stopped on a slope break all 4 tires loose and simply slide sideways into the opposite lane, or into the near snowbank more than once. I tend to shoot for a very steady and even 20-25mph.
  • Not too close: Give the car in front of you a lot of extra space. If it comes to a stop suddenly (for example, by hitting a snowbank because it’s slippery out), you will need to have plenty of space to stop… because it’s slippery out.

Resources – Tom put together a handy website where you can check the weather forecast for different parts of the park. Because the elevation changes so much, storms can come in as rain (no chains) at lower elevations and as snow up high (chains).

209-372-0200 then 1, and 1 again – this is the best resource for current in-park road conditions. It is usually the first resource updated when road conditions change. We use it all the time.


Is this still confusing? Do you have any questions or suggestions? Feel free to contact us!