A semi overturned on I-5 a little before 4:00 p.m. Thursday causing a huge traffic backup in the northbound lanes.

The truck rolled blocking both northbound lanes at milepost 74 approximately two miles south of Wolf Creek and traffic was only able to traverse the roadway single file on the shoulder. The truck was carrying bales of cardboard which spilled over onto the roadway into the northbound and southbound lanes.

The Oregon State Police say the load in the truck shifted causing the rollover.

No injuries were reported in the incident.