A tractor-trailer overturned Monday afternoon on Highway 13 in Moffat County in northwest Colorado.
Colorado State Patrol says the truck was hauling 73 head of cattle.
Troopers say some of the cattle were killed and others were injured in the crash.
The truck's driver suffered minor injuries.
Highway 13 was closed in both directions for hours.
Troopers and others set up a temporary holding pen for the surviving cattle.