Demolition begins Sunday on the snowshed that has covered the westbound lanes of Interstate 90 at Snoqualmie Pass for 64 years.
The work is part of the $551 million Transportation Department project to improve traffic flow over the pass, especially in winter.
The Yakima Herald-Republic reports the area where the snowshed stands will be replaced with bridges that will carry traffic over the avalanche chutes.
The Snoqualmie Pass improvements are scheduled to be completed in 2018. Drivers can expect delays and detours while the work continues.
An average of 28,000 vehicles drive over Snoqualmie Pass each day.