North Rough Ridge, close to where the fire burned, is covered in dry snow tussock up to 1m tall and Station Officer Rob Hazlett, of Ranfurly, said if the flames had reached the tussock, firefighters would have required ''20 helicopters'' rather than the two used to fight the fire.
The two helicopters were equipped with monsoon buckets that were refilled from a nearby irrigation dam.
More than 50 firefighters and volunteers and nine appliances and tankers also attended.
Mr Hazlett said a wind change made the work more challenging.
''It was all we could do to stop it.''
The fire, which started about 2pm and was brought under control by 4.30pm, was thought to have been caused by sparks from a digger working in a rocky area, he said.
Peter Hore, who owns Cornaig Farm, where the fire started, said he told his wife at lunch he thought there would be a ''bloody big fire'' soon.
''The last place I thought there would be a fire was my place.''
When he received a phone call about the fire, he reacted ''very quickly'' to shift ''a couple of thousand'' sheep away from the area, out of harm's way.
''I thank the local fire brigades and rural fire party ... I could not give them enough praise.''
Mr Hore, who had ''comprehensive'' insurance, said the land would probably not recover until next spring.
Otago Rural Fire Authority rural fire officer Mark Hutton said it was a timely reminder farming operations needed to be undertaken with awareness of the ''extreme fire danger conditions''.
Two fire crews remained at the scene last night to monitor and control hotspots.
An investigation into the cause of the fire was under way.
