Dannevirke police are still investigating what caused a stock truck to crash on State Highway 2 at Butcher's Creek on Sunday afternoon, closing the road for six hours.
"The truck and trailer, carting lambs north, crossed the bridge and hit a bank, before crashing 20 metres to the bottom of a cliff, killing 260 of the 530 lambs on board," Constable Phil Black of the Dannevirke police said.
"What actually caused the crash is still to be determined."
The three occupants - the driver and a father and son - received minor injuries and were "very lucky", Mr Black said.
"It was a big mission to round up the surviving sheep and eight are still running over the hills somewhere," Mr Black said. "But we were very lucky two local contractors, Hermanson's and Haycock's, arrived on the scene of the crash on Sunday with tractors and diggers to help out. We also had great help from Cameron Rolston, Brandon Richards, Richard O'Brien and Jason Henry. They went well beyond what was expected and I want to personally thank them."
Mr Black said the owners of Norsewood's Scandi Superette and partners of the Norsewood Volunteer Fire Brigade helped by providing food and drink for emergency services.
"They are all amazing local people and went far beyond the call of duty. I can't praise them enough."
Yesterday, two diversions were in place from 10am as a crane was called in to lift the wrecked cab of the truck.