According to the Oregon State Department of Transportation,  they have to be off by midnight Monday.

Despite some late snow and icy activity on Oregon's highways,  studded tires must be off by Monday.   Given current upcoming weather forecasts, Oregon officials felt there was no need to extend the season.

According to Oregon officials at the DOT, a study done back in 2000 shows that studded tires do about $40 million dollars worth of damage to roads in city streets, county roads and state highways.  They recommend other forms of traction if needed in snow, including temporary chains if it's deep enough,  or especially non-studded traction all-weather tires.

The website tripcheck.com has updated travel information and road conditions for those ready to make trips.