A police spokesman says snow-and-ice caused Tuesday's crash on Highway 204 in Umatilla County.
The chaos started when a semi-truck slid and got stuck on the highway, causing two other vehicles to collide. It ended a couple vehicles later, when the truck carrying the cattle collided with a van that had stopped just before the crash site.
The woman driving the van was taken a Pendleton hospital for treatment of minor injuries. There were no other injuries beyond what happened to the cattle.
Police say the crash investigation remains active.