Winter

Do You Need Snow Tires to Drive Up the Cottonwood Canyons?

There is a set of beacons at the mouth of Little Cottonwood Canyon, a few minutes east of Sandy up 9400 South, and when they start flashing the question of whether you need snow tires for the Cottonwood canyons stops being a matter of opinion. Utah's Traction Law takes over, an officer at the canyon entrance decides whether your vehicle goes up, and the canyons carry the strictest requirements in the state. This guide covers what actually qualifies, who checks, and what happens to the drivers who go up anyway.

Utah's Traction Law Answers This, Not Your Weather App

Whether you need snow tires for the Cottonwood canyons is decided by Utah Administrative Rule R920‒6, the Adverse Weather Traction Requirements, which UDOT and law enforcement put into effect during severe winter conditions. Big Cottonwood (SR-190) and Little Cottonwood (SR-210) sit in their own category with stricter requirements than other roads in the state.

Two changes are worth understanding before you plan a ski morning:

UDOT can put traction requirements in place up to 24 hours before a storm begins, so the rule can be live under a blue sky.
The rule created a Class 3 designation specifically for the Cottonwoods, which is where the 5/32 inch tread minimum comes from.

The decision to require traction devices is made by UDOT, the Utah Highway Patrol or a designated local law enforcement agency, and the flashing beacons outside the canyon mouths are how you find out it is in effect.

What Actually Counts As Legal Traction Up There

When the beacons are flashing, every vehicle entering Big or Little Cottonwood needs at least 5/32 inch of tread depth, and what the tires have to be rated for depends on your drivetrain. UDOT's Cottonwood Canyons traction law page spells out both cases:

All-wheel drive and four-wheel drive: M+S or snow-rated tires on all four wheels is the minimum. Chains, snow socks or 3PMSF tires on all wheels are also acceptable and give the most reliable traction.
Two-wheel drive: 3PMSF tires on all wheels is the minimum, or traction devices on at least two drive wheels.

The two ratings are not interchangeable. M+S means a tire meets the Rubber Manufacturers Association guideline for mud and snow, which is better than a summer tire but says nothing about ice, slush or fresh snow. The three-peak mountain snowflake, 3PMSF, is a stricter standard rated for severe snow service, using a rubber compound that keeps its grip on cold pavement.

Already Off the Road in a Canyon or on a Sandy Side Street?

Tread depth stops mattering the moment a wheel is in the snowbank. Towing Sandy runs snow and ice recovery through the winter across Sandy and Salt Lake County, and a truck with the right gear beats a shove from a stranger every time.

Call Now (801) 618-2334

Sandy Police Check Tires at the Mouth of Little Cottonwood

Enforcement in Little Cottonwood is run by the Sandy City Police Department at the canyon mouth, with Cottonwood Heights police covering Big Cottonwood and the Salt Lake County Sheriff's Office assisting at the Snowbird merge point and inside both canyons. The Utah Legislature funded the additional enforcement through HB 488, so the checkpoints are staffed rather than occasional.

Officers deploy when the traction lights are on during the winter season while the resorts are open, concentrating on the morning uphill and evening downhill commutes. The turnaround points sit at the canyon entrances, which means a non-compliant vehicle gets sent back down rather than waved through. If you need to fit chains, you are expected to pull out of the line and do it at a designated chain-up area instead of holding up the queue.

UDOT also runs a free, voluntary sticker program each winter: participating tire shops around Sandy, including locations along State Street and 700 East, inspect tires at no charge and put a windshield sticker on vehicles that meet the standard. A sticker speeds up the check but it is not required, it does not guarantee entry, and it does not get you up during a closure.

Why All-Season Tires Usually Do Not Qualify

Most all-season tires do not earn the 3PMSF symbol, and the reason is chemistry rather than tread pattern: all-season and summer compounds harden below about 40 degrees, which is most of a Cottonwood winter morning. That matters most for two-wheel-drive drivers, since 3PMSF on all four wheels is their minimum. A set of all-seasons with plenty of tread left can still be turned around at the mouth of the canyon.

Meeting the Requirement Is Not the Same As Being Safe

Compliant vehicles slide off these canyons all winter, and UDOT says so directly. While plenty of the slide-offs involve out-of-state two-wheel-drive cars with no traction devices at all, many are Utah residents whose vehicles do meet the requirements; worn tread, too much speed for the conditions and plain inexperience in mountain snow account for the rest. Legal equipment is a floor, not a guarantee.

Two practical details people forget. There are no gas stations in either canyon, so fuel, water, snacks and a phone charger belong in the car before you start up. And if you are not confident driving snow at grade, UDOT's own recommendation is the ski bus or waiting for conditions to improve rather than testing it above Snowbird.

What Happens After a Car Goes Off the Road Up There

A canyon slide-off is a recovery job, not a simple hook, and that changes who you need. A vehicle nosed into a snowbank or hung up below the shoulder has to be pulled back to the roadway before it can be towed anywhere, which is winch out and recovery work rather than a straight snow and ice recovery lift. On a narrow canyon road with traffic still moving past, it also has to be done without turning one stuck car into a closed road.

Stay in your vehicle with the seat belt on while you wait, the same as you would on the freeway, and give the dispatcher the canyon, the direction you were travelling and the nearest landmark or mile marker. Getting a truck moving early matters more here than in the valley, because storm traffic, avalanche control and a single blocked lane can turn a twenty-minute run up SR-210 into something much longer.

Sources

UDOT Traction Law, Cottonwood Canyons Roads to Recreation, Utah Department of Transportation
Cottonwood Canyons Sticker Program, Utah Department of Transportation
Rule R920‒6, Adverse Weather Traction Requirements, Utah Office of Administrative Rules

Snowbank Recovery in the Cottonwoods and Across Sandy

Right tires, wrong corner: it happens to careful drivers every winter up here. Tell us which canyon or which street, which direction you were heading and the nearest marker, and we bring the winch and the gear the job actually needs.