The accident was reported just before 4 p.m. on US 285, near Parmalee Gulch road. Colorado State Patrol says the semi was hauling about 60 cows when it tipped.

An unknown number of cattle died at the scene. Investigators shut down parts of the highway in both directions for several hours to clear the road.

"We have not seen many incidents of this type, but with the help of the animal rescue team we were able to create a small corral to herd the cattle safely," said Capt. Dan Hatlestad, a spokesperson for Intercanyon Fire and Rescue.

Officials say most of the cattle appeared to be in good health and were transported to the Jefferson County Fairgrounds where they will be evaluated by a state veterinarian.

The highway re-opened later Saturday night.