A controlled burn of gorse and heather in County Londonderry turned into a blaze across 150 acres of land.
The fire burnt out of control between Dungiven and Maghera after the wind speed and wind direction changed.
Five fire engines and approximately 30 firefighters from the Northern Ireland Fire and Rescue Service attended the scene.
The blaze has since been brought under control.
Station Commander Paul Coyle said the task was made more difficult by the fire's location.
"It was compounded by the distance our firefighters had to travel quite a distance by foot over rough terrain," he said.
Mr Coyle said landowners conducting controlled burns should be aware of changes in wind speed and direction.
"We would ask that they have adequate supervision of any burn that they're intending to do and that they confine their burns to a small area.
"They should also take into consideration the wind speed and direction and be aware of how quickly the wind can change."