A cattle trailer overturned in Harrisonville and police estimate that 40 to 50 cattle have died in the crash.
Officers were working early Friday to corral other cattle that were running loose near the crash site.
Northbound Interstate 49 traffic was closed for several hours at the Commercial Street exit due to the crash, causing massive delays for commuters.
Harrisonville Lt. Chris Osterberg said the crash happened around 4:30 a.m. Officers arrived and found a man and a woman in the truck. They were both taken to a hospital with minor injuries.
Police said the truck was pulling a trailer with "80 to 100 head of cattle." It's unclear where they were going.
By 7:45 a.m., police said nearly all the cattle had been rounded up and were being taken from the scene in trailers. Some are expected to be looked at by a veterinarian, police said.
The Cass County Sheriff's Office and the Missouri State Highway Patrol assisted at the scene.
Police said the cause of the crash remains under investigation.