Emergency services rushed to several grass fires along State Highway 8 in the Mackenzie District, Canterbury, which were brought under control by the swift work of helicopters.
A truck passing through the area had caught fire, spreading the flames near Lake Pukaki before becoming engulfed itself.
A Fire and Emergency New Zealand (Fenz) spokesman Andrew Norris said the fires had taken off between Twizel and Tekapo.
"We believe there were probably in excess of 10 fires ... ranging in size from 200sq m to sort of 900sq m in size.
"But they were quickly dealt with once the helicopters got there."