2022 North Cascades Spring Clearing: Assessment Day

By Lauren Loebsack

The spring clearing of the State Route 20 - North Cascades Highway is a highly anticipated event for both the public and  our avalanche and maintenance crews who do the work.  There are many factors that shape the spring clearing plan, from the amount and type of snow in the avalanche paths, to spring weather patterns and balancing the schedule with other important spring maintenance in the area.

Crews assess the North Cascades Highway

The clearing plan takes shape when our avalanche and maintenance crews meet onsite to explore beyond the seasonal closure point.  It's a team discussion, with the two crews reviewing conditions together. The avalanche crew looks at the snow load in avalanche starting zones, which is the area at the top of an avalanche path where the snow accumulates. They measure the depths of the slides and check for debris to determine what equipment will be needed for the clearing effort.

The snow level at Washington Pass

The maintenance crew is also interested in the conditions of the snow in the slides and the depth of the snow "on the level," a term that refers to the conditions on the highway outside of the avalanche paths. Hard packed snow or snow filled with rock and debris cannot be cleared with blowers and requires loaders to remove the snow and materials one bucket load at a time.

A worker checks the snow pack

The crews also identify hazard trees still hanging to the mountainsides above the highway and work with the U.S. Forest Service to safely remove them.

Snow conditions on the North Cascades Highway

Special equipment is rented for the clearing effort, including a Catepillar D8 and Catepillar D6. Depending on the assessment, other equipment may be added to the fleet including a grader, loaders, excavators and blowers.

When our crews went out last week to begin the assessment, the weather was underwhelming with a low fog that scuttled plans for a drone flyover of some of the starting zones that cannot be seen from the highway. The avalanche crew determined the snow depth in the avalanche paths is normal to below average and the condition of the snow is soft, meaning the work can start soon.

Crews started clearing this week, beginning with grading out the berm at Early Winters campground at milepost 178 and will work west. The assessment is our starting point, but it is still difficult to know exactly how long the clearing effort will take and each year is slightly different.  Spring storms could redirect crews back to plowing snow elsewhere and avalanche slides may be dirtier than expected. The spring clearing effort typically takes between 4 and 6 weeks.

In addition to regular spring clearing, expectant travelers should be aware of work on the west side of the North Cascades between Marblemount and Newhalem. This work is necessary following the November 2021 flood that washed out the roadway near milepost 113 and has kept traffic reduced to a single lane with a signal. This is expected to cause some delays during peak summer travel. In December, crew collected extensive core samples for geotechnical analysis. We are now working with our bridge designers on a repair plan, which will include constructing a new stabilizing wall in this area. This project is in the design phase where our engineers work to put together the plan to build the wall. Our crews and contractor will make every effort to expedite this work and return the road to normal operations, however some of our work is dependent on variables beyond our control such as cooperation from the weather. We know that these types of delays are inconvenient, so we want you to be able to plan ahead for your travel over the North Cascades Highway this year. And please know how much we appreciate your patience with us as we work on these repairs.

In the meantime, there's several ways you can follow our progress on the 2022 spring clearing work.  You can follow us on social, check out pics from the clearing work on Flickr and sign up for the North Cascades Highway Newsletter through GovDelivery.

Share :