State troopers and medics responded to the scene, on I-90 near the town of Vantage, after receiving a report of a serious crash.
At least 15 cars and nine semi trucks collided in the eastbound lanes, about 17 miles east of Ellensburg. Westbound lanes also were closed temporarily due to intermittent poor visibility, but have since reopened.
There were reports of multiple injuries.
The cause of the pileup remains under investigation.
This is a developing news story. More information will be posted as it becomes available.