Experts from Scottish Natural Heritage say it will yake years for moorland to recover following a blaze which took hold on Monday afternoon.
More than 1,000 acres around Criffel, south of Dumfries, was affected.
At its height the flames could be seen across the Solway Firth in north Cumbria.
Fire brigade bosses say 60 people were involved in an operation to extinguish the flames
A Royal Navy Sea King helicopter was also used to ferry firefighters to the scene.
The fire came within just a few metres of extensive forest land. The Forestry Commission says there could have been a major environmental disaster if the flames had taken hold there.
Today Hamish McGhie from Dumfries and Galloway Fire and Rescue Service confirmed the operation will have cost tens of thousans of pounds.
The cause of the fire is still being investigated.
Cllr Ian Blake from Dumfries and Galloway Police Fire and Rescue Committee has asked for a report to be completed on the blaze.