Washington Mountain Passes

Washington State Department of Transportation publishes it, at the WSDOT mountain pass report, and that is the page to plan on. Washington gates are opened and closed by people looking at the road, sometimes several times in a week. What this page holds is the record of how Washington gates have behaved in past seasons, the measured snowpack at the stations nearest them, and the link and phone number for the agency.

It depends heavily on which road, which is why this page gives a figure per road rather than one for the state. North Cascades Highway has the deepest record here: across 53 recorded seasons its median closing is November 24, with the earliest on record October 17 in 2003 and the latest January 3 in 1989. That is a spread of 78 days around a median, which is the number that matters: the median tells you when to start paying attention and the spread tells you how little it guarantees.

Snoqualmie Pass on I-90, Stevens Pass on US 2, White Pass on US 12, Blewett Pass on US 97, Sherman Pass on SR 20, Satus Pass on US 97, Loup Loup Pass on SR 20, Wauconda Pass on SR 20, Disautel Pass on SR 155, Manastash Ridge on I-82, Crystal to Greenwater on SR 410, Tiger Mountain on SR 18. These are maintained through the winter and have no seasonal date at all. What varies on them is traction requirements, avalanche control holds and storm closures that last hours rather than months. They are on this page because they are searched for in exactly the same words as the gated ones, and telling the two apart is most of the value of a page like this.

Sherman Pass on SR 20, at 5,575 feet. The highest pass in Washington kept open through the winter, and the reason route numbers are a bad way to talk about passes: it shares SR 20 with the North Cascades Highway, which closes every year.

This page reads it live from the USDA Natural Resources Conservation Service SNOTEL network, which has 7 stations named for and sited at a Washington pass on this page. Those are physical measurements, a sonic ranger over the snow and a fluid pillow under it, taken at a named station with a stated elevation and a stated date. They are not roadway measurements: a SNOTEL site is an unplowed forest clearing that can sit hundreds of feet above or below the pavement, so read the depth as what the mountain is holding rather than as what the road looks like.

Because no agency publishes one. Mount Baker Highway to Artist Point is gated for the winter and has no year by year record from any agency: isolated single seasons appear in press releases, and that is all, so there is no median to compute. If WSDOT or a park starts publishing a table, it will appear here.

Because WSDOT writes its detailed pass reports from November to April and stops for the summer. In early September fourteen of the sixteen pass records carried the off season notice and only Satus Pass carried live weather and road values, which is the normal state of the feed for about half the year, so an off season row is the feed working normally. The timestamp shown is the moment this page read the feed, since the feed’s own display date field is empty.

This is the trap in Washington and it catches almost everybody. Two passes carry the SR 20 label and they behave in opposite ways. The North Cascades Highway over Rainy and Washington passes closes every winter, usually from late November until April. Sherman Pass, 150 miles east and 98 feet higher, is the highest pass in the state kept open year round. Searching by route number finds whichever one an index happened to file first. Search by pass name, and check the name on any report before you trust it.

Washington State Department of Transportation at the WSDOT mountain pass report. WSDOT also runs a recorded line on 511, the Washington travel information line, or 1-800-695-7623 from outside the state. Every one of those links was checked on 4 September 2026 and returned a working page. They are the source of record for anything happening today.

16: 4 that close behind a gate for the winter and 12 that stay open and are chain or traction controlled instead. 3 of them carry a published year by year record, which is what the tables on this page are built from. The list is the Washington passes that appear in a machine readable agency feed, have a snowpack station named after them, or carry a published date record, which is the inventory that can be checked against a source.