I-80 Donner Pass chain control: checkpoints, truck codes and closures

I-80 chain control is in effect whenever Caltrans posts R-1, R-2 or R-3 between Colfax and Truckee, most often from Kingvale to the Donner Lake interchange eastbound and from Truckee to Kingvale westbound. The live strip above shows today's I-80 status and the resorts along it.

Where the checkpoints are

Caltrans reports I-80 by checkpoint, and the I-80 page lists them in driving order with the level at each one. Eastbound, climbing from Sacramento, they are Applegate, Colfax, Gold Run, Alta, Baxter, Drum, Whitmore, Nyack, Yuba Gap, Cisco Grove, Rainbow, Kingvale, Castle Peak (the Boreal exit), the Donner Lake interchange and Truckee. Westbound the same points run in reverse.

The most common control covers the summit itself: R-1 or R-2 from Kingvale eastbound over Donner Summit (just over 7,000 feet) to the Donner Lake interchange, and from Truckee westbound back to Kingvale. As the snow level drops the eastbound start point moves down the hill, first to Rainbow and Cisco Grove, then Yuba Gap, Baxter and Alta, and in a serious storm to Colfax or Applegate, which puts close to 40 miles of interstate under chain control.

What a storm usually looks like

1. Snow starts sticking above 6,000 feet. R-1 goes up at Kingvale and at the Donner Lake interchange; trucks are screened for chains (TS).
2. The storm builds. The level rises to R-2 and the control extends down to Cisco Grove, Baxter or Alta. Truck-trailer combinations are turned around (TTA) or held (TH). This is when the chain installers along the grade are busiest.
3. Spinouts, whiteout or avalanche control. Caltrans holds traffic at Applegate or Colfax eastbound and at Truckee westbound, or closes the road outright, often without ever posting R-3.
4. Clearing. The control shrinks back toward the summit, drops to R-1 and finally to R-0, frequently the morning after the storm once the pavement has stopped refreezing.

Requirements change without notice at every step, so check the live status before you leave and read the signs on the way up.

Truck codes on I-80

I-80 is a major freight route, so Donner Summit carries truck-only codes that do not apply to cars. You will see them on the message boards and on the Snowy Roads checkpoint list.

The passenger-vehicle levels are explained in R-1 vs R-2 vs R-3.

When Caltrans closes I-80

Closures come from jackknifed trucks and spinouts blocking lanes, whiteout on the summit, avalanche control above the roadway and, on the worst days, more vehicles without chains than the checkpoints can turn around. Highways are often closed before R-3 is imposed. Eastbound traffic is typically held at Applegate or Colfax, westbound at Truckee, and the Nevada DOT holds westbound traffic on its side of the state line. There is no practical detour: US-50 is usually under its own control, and SR-20 and SR-49 lead back to I-80. Snowy Roads shows a closure as "Road closed at pass" on the I-80 chip; the only plan is to wait for the reopening or turn around.

Resorts off I-80

• Sugar Bowl, at the Soda Springs / Norden exit on top of Donner Summit, together with Donner Ski Ranch and Soda Springs on old Highway 40. These sit inside the control area whenever one is posted.
• Boreal, at the Castle Peak exit just east of the summit.
• Tahoe Donner, in Truckee.
• Palisades Tahoe, via SR-89 south from Truckee through Olympic Valley. SR-89 gets its own control between Truckee and Tahoe City.
• Northstar, via SR-267 south from Truckee over Brockway Summit, which is often under control when I-80 is.
• Mt. Rose and Diamond Peak from the Reno side, on Nevada DOT roads.

Driving from Reno

Westbound drivers meet Nevada DOT requirements first, then the Caltrans control at Truckee or the Donner Lake interchange, which runs over the summit to Kingvale. The eastbound holding points do not affect you, but a full closure does: Nevada holds westbound traffic on its side until Caltrans reopens.

Before you go

Open the I-80 page for the checkpoint list, cameras at Kingvale, Castle Peak and Donner Lake, and the message boards, all refreshed every 3 minutes from Caltrans data. Caltrans QuickMap (quickmap.dot.ca.gov) and 1-800-427-7623 are the official sources. Always carry chains, and see how to put on chains before your first storm.