Firefighters from Mosgiel were called to the scene at 3.15pm to attend a scrub fire threatening a block of pine trees, near the intersection of State Highway 1 and Riverside Rd.
Fire and Emergency New Zealand shift manager Andrew Norris said the fire was about 20m by 20m and crews had to walk up a steep bank to battle the blaze.
"There was no way of getting a truck anywhere near it."
A HeliOtago helicopter armed with a monsoon bucket was requested, getting to work battling the blaze before being stood down about 4.50pm, he said.
Shortly after 5pm the fire was well contained, and the crew from Mosgiel went home following the arrival of another from Waihola who were "mopping up" and dampening down hot spots.
The Waihola volunteers were back at their station by 6pm.
Mr Norris said the cause of the fire had yet to be determined.
