The blaze between Port and Kilcar covered a large area.
Smoke could be seen for miles around.
It is illegal to set fires at this time of the year – but this blaze could have started accidentally.
High temperatures and strong winds helped spread the fire, one of a number of gorse fires reported to donegaldaily.com on Saturday night.
Our picture was taken by donegaldaily.com reader Claire Coughlan.
Anyone seeing a fire should call the emergency services immediately.
Last year’s fires – over a two week period – caused millions of euro worth of damage.
“We just hope this isn’t the start of another outbreak,” said one senior Donegal County fire officer.
“Conditions on Saturday were ripe for gorse fires. It was extremely hot and very very windy which means they can spread quickly.
“You’ve heard of the phrase ‘spreading like wild fire’ – this is what it looks like.”