A semitruck has rolled over on westbound I-90 near Cle Elum on Thursday afternoon, causing traffic to back up.
Washington State Patrol Trooper John Bryant said traffic is getting by in the right lane, but backups are expected to last a while.
The Washington State Department of Transportation tweeted just before 5 p.m. that there's a seven-mile backup.
The driver of the semi was not injured in the crash, Bryant said.
The cause of the crash is under investigation.