How do you know if a mountain pass is open?

The state DOT's road report is the only official answer. Some states publish a separate pass report, and Washington posts it by direction. Others list closures and restrictions by route, and a route with no closure listed is not the same as a route confirmed open. A camera shows snow on the road. It does not say the road is open. Read the report, then look at the camera.

Where is the official answer for each state?

Most states also answer 511 by phone. Washington does not. WSDOT shut its 511 phone line on May 19, 2023 and points callers to its app and website. (WSDOT) Our page on what 511 is explains how the number works in each state.

What does the report actually say?

Three things. Whether the road is open, closed, or open with a restriction. The traction or chain requirement, which is law. And the road surface, in phrases like bare and wet or compact snow and ice. Washington posts eastbound and westbound separately, so read your direction. (WSDOT) Some roads also close for the whole season on a date the agency sets. Those are on our seasonal closures pages, not in the daily report.

How does MileCheck show it?

1. Pass pages. Each of our pass pages reads the state's DOT feed and lists the current events for that pass next to its camera. Snoqualmie, Stevens, Donner, Eisenhower, Vail, Parleys, Siskiyou, Cabbage Hill and the Grapevine are there.
2. Cameras. DOT cameras by state and city show the road itself. A white road with no tracks and a line of stopped trucks tells you more than any text, but it still does not say open.
3. Closures. The live closures map puts every state's closure feed on one map, and each road conditions page lists them for that state.
4. Plows. The snowplow map shows truck positions from the states and provinces that publish them. A pin is where the truck is. It is not proof the road was worked, and it is not an open-or-closed status.

The app shows the same feeds around your own position, with your nearest mile marker on screen. The mile marker works offline. The feeds need a connection.

What do I do if the pass is closed?

Wait where there are services, or take the detour the DOT names. Both I-90 detours in Washington cross their own passes with their own chain rules. Wyoming closures roll back to the next town so drivers are not stranded on the road. Read how do you drive safely in winter conditions before you go, and which highways are most dangerous in winter for the closure records each DOT publishes.

Questions, answered

Official pages read October 15, 2026. Pass status changes by the hour, so read the DOT report before you leave.

Related: Which highways are most dangerous in winter? · How do you drive safely in winter conditions? · Mountain pass pages · Live closures map · Live snowplow map · Seasonal closures · What is 511?