North Cascades Highway closure dates and why SR 20 shuts

The North Cascades Highway, State Route 20, closes for the winter on no set date. The Washington State Department of Transportation (WSDOT) shuts it when snow and avalanche danger say so, and the 53 closings on its table of opening and closing dates from 1972 through 2025 ran from October 17 to January 3, with a middle date of November 24 by this site's count. As of October 21, 2026, WSDOT had posted no closing notice for the winter of 2026 to 2027, and its pass report for the road, dated June 14, listed it open. From Enumclaw it is about 150 road miles to Newhalem, where WSDOT's December 2025 notice says the west gate is typically moved later in the season, depending on conditions, so confirm the road before you drive up.

The earliest closing on that table came from a flood, by WSDOT's account in 2004. The table dates it October 17, 2003, and a WSDOT release that April said flooding and rockslides had "forced the highway's earliest closure ever." The agency's December 2025 closing notice gives a different year: "The earliest closing date for the North Cascades Highway was Oct. 17, 2007." The notice links that phrase to the table, which has the road closing on December 4 in 2007.

When does the North Cascades Highway usually close?

Usually in November: 34 of the 53 closings on WSDOT's table fall in that month, 16 in December, two in October and one, on January 3, 1990, in January. The middle date, with half the closings before it and half after, is November 24, and each decade's middle date from the 1970s through the 2010s lands within a week of that; for 2020 through 2025 it is November 17. These counts and middle dates are this site's arithmetic from the table, which gives dates and no statistics. The National Park Service says snow and avalanche hazards usually close the road in late November or early December.

The table dates the ten closings from 2016 through 2025 to November 18, 2016; November 10, 2017; November 28, 2018; December 11, 2019; November 16, 2020; November 15, 2021; November 3, 2022; November 30, 2023; November 18, 2024; and December 4, 2025, the first December closing since 2019.

The table gives one date a season and does not say what that date marks. For 2021 it lists November 15, the planned closing date WSDOT announced that October, though the road closed on November 10, KING 5 reported. For 2022 it lists November 3, the day the road partially closed for avalanche danger, though WSDOT announced on November 8 that it would stay closed for the winter. For 2024 it lists November 18, the day WSDOT declared the season closed after a weekend storm closure. The Cascadia Daily News reported the last two sequences. A table date can be days off from the day the road shut or the day anyone knew the season was over, which makes it a record and not a forecast.

Is the North Cascades Highway open?

On October 21, 2026, WSDOT's pass report for the highway was dated June 14 and listed the road open, and the newest release in WSDOT's newsroom, dated October 20, had no closing notice. The pass page says it traditionally reports weather and road conditions from November 1 to April 1 and posts updates outside those dates when weather affects travel, and WSDOT's closing notice also points drivers to its travel map, app and email alerts. In 2021 WSDOT tried a planned date, setting November 15 in October "to allow travelers to plan ahead with more certainty," and then moved the closing up five days. Notice can be short: WSDOT announced the closing on Tuesday, December 2, 2025, the Cascadia Daily News reported, though the notice on its site is dated December 3 and sets the closing for 6 p.m. on Thursday, December 4. A storm closure can also come first and lift, as one did from November 13 to 17, 2025, the Cascadia Daily News reported.

Why does Highway 20 close for the winter?

Snow and avalanche danger close it, and WSDOT decides when. Its December 2025 notice said the road would close for the winter "due to conditions and avalanche risk," citing snow loads and a snow forecast. On I-90 at Snoqualmie Pass and US 2 at Stevens Pass, WSDOT sets off slides on purpose with explosives and artillery, a winter-long job called avalanche control. For Chinook Pass, Cayuse Pass and this highway it closes the road for the season instead, because, its avalanche page says, "avalanche control work in those areas is too hazardous." The same page says SR 20 east of Washington Pass is among the top areas in the United States for avalanche paths per mile of highway.

Where are the gates, and how far is that from Enumclaw?

The December 2025 notice put the closure between the Ross Dam trailhead on the west, at milepost 134, and the Silver Star gate on the east, at milepost 171. Mileposts count distance along the route, so that is 37 miles by subtraction. The notice said the closure points are typically moved later in the season to lower gates at Newhalem, milepost 120, and Early Winters, milepost 178, which by the same subtraction would make the closed stretch 58 miles. WSDOT's pages give three pairs of mileposts for the winter of 2025 to 2026: 134 and 171 in that notice, 134 and 178 in a January 23, 2026 release, and 131 and 178 in the repair page's milestone for December 4. The notice also gives the highway's two high passes, Rainy and Washington, as 4,862 and 5,475 feet, where WSDOT's avalanche page says 4,855 and 5,477.

From Enumclaw City Hall it is about 150 road miles to Newhalem by a routing engine's measure, and 14 more by the mileposts to the Ross Dam trailhead. The seasonal closure leaves the road below the gates alone, and the eagle-watching reach at Marblemount, covered in the Skagit River bald eagles guide, lies on that side.

What were the earliest and latest closings?

The table's earliest closing is October 17, 2003 and its latest January 3, 1990, which the notice repeats. The notice's 2007 does not match the table, and WSDOT's April 2004 release tied the earliest closure to the flooding and rockslides of autumn 2003, so this site goes with 2003. By WhatcomTalk's 2024 account the closing was a washout: a landslide in the storm of October 16 and 17, 2003 took out 150 feet of road at Pyramid Creek. The 2004 release said October flooding and November rockslides forced the closing and that the official season closure was announced on December 15.

Has the North Cascades Highway ever stayed open all winter?

The table shows it once, in the winter of 1976 to 1977: it lists no closing for 1976 and no opening for 1977, and the road next closed on November 23, 1977. The Associated Press said in 2005 that so little snow fell the highway was never closed, and HistoryLink calls it an infamously warm winter. The table has the same gap for State Route 410 over Chinook Pass, the closing nearest Enumclaw, whose dates are in the Chinook Pass closing guide.

When does the North Cascades Highway reopen?

Usually in April: the middle opening on the table is April 22, across 52 openings from 1973 through 2025 (1977 has none, since the road never closed the winter before), with 29 in April, 18 in May, four in March and one in June. The National Park Service says it usually reopens in April or early May. The earliest was March 10, 2005, which the Associated Press called the earliest spring opening since the road was completed in 1972, and the latest June 14, 1974.

Why did the highway reopen so late in 2026?

Two atmospheric river storms, long bands of water vapor, broke the road, WSDOT's repair page says. On December 12, 2025, in the same week of storms that closed Highway 410 between Enumclaw and Greenwater (see the atmospheric river guide and the White River flood guide), a blocked culvert near milepost 145 sent water across SR 20 and undermined the roadbed. WSDOT counted more than 1,000 feet of lane undermined or collapsed and about 15 damaged or buried culverts, the pipes that carry streams under the road. On March 17, 2026, a rockslide about 200 feet wide fell near Diablo Lake at milepost 131. The damage sat near 2,170 feet, WSDOT said, under snow until crews could assess it in March.

The east side reopened as far as Porcupine Creek, milepost 156, on April 30, the west side to the Ross Dam trailhead on May 30, and the whole road on Sunday, June 14. WSDOT's blog says that matches 1974 for the latest opening since it began keeping records in 1972. The repair page says June 14 in its text and June 24 in its milestone list, and on October 21, 2026 the table's 2026 row recorded only the April 30 partial reopening. From the December 4 closing to June 14 is 192 days, which by this site's count is second to the 205 days of 1973 to 1974 in the table.

What to check before you drive up from Enumclaw

Open WSDOT's pass report and travel map the morning you leave. On WSDOT's table, ten of the 53 closings are dated before November 15 and 17 on or after December 1, so a heavy-snow forecast in late autumn can be a last call. When SR 20 is shut, the way around to Winthrop, over Snoqualmie Pass on I-90 and Blewett Pass on US 97, is about 243 road miles from Enumclaw City Hall by a routing engine, against about 223 over the North Cascades; WSDOT posts a pass report for each. The winter road to Yakima guide explains the chain rules on Snoqualmie Pass.