(Wilsonville, OR) -- A trailer carrying a load of cattle overturned on I-5 in Wilsonville yesterday afternoon. A total of 31 cows were in the trailer, and many of them got loose on the freeway. Both north and southbound lanes were closed while the cattle were herded toward another trailer. The driver of the truck that crashed didn't need to be transported to a hospital. Oregon State Police are investigating the cause of the crash.