Betsy slipped her harness when on a walk with her owners on the summit plateau of Cader Idris.
Desperate searches by friends and family failed to find her and a major exercise got underway with experts from Aberdyfi search and rescue team volunteering to go out in bad weather to help find her.
Betsy's ordeal began at midday on Saturday when the small, pointer cross dog ran from her owners.
They searched for hours but had to leave the mountain without her returning on Sunday with friends and family to look in bad weather.
Graham O'Hanlon, a member of the search and rescue team, said: "Late on Monday afternoon, a searcher reported hearing what he thought was a dog wimpering in an area of steep craggy ground to the north east of Llyn Cau and with a specific target to explore, the owners requested mountain rescue assistance.
"With night rapidly falling, and rain falling even faster, three team volunteers headed up to see if they could confirm the reported noise, but the weather was too bad to see or hear anything."
"They talked to members of the group searching for the dog who said they were returning at first light and team co-ordinators felt that a mountain rescue presence on the hill might provide alternative options to them putting themselves at risk should the dog be spotted."
A dozen team volunteers made themselves available to take part in the search for Betsy on Tuesday morning with the technical-rope rescuers approaching the area from above and a second party scanning the crags with binoculars from below."
"A dog was heard howling on the wind, and news came through that one of the owners had located the dog on a rocky buttress but was unable to reach her.
"Team volunteers were able to move quickly and rigged a simple rope system to access the dog, who was cold and hungry but otherwise in surprisingly good condition given her three nights out in some appalling weather.
"Betsy was quickly reunited with her owners, and everyone made their way safely back down."
"The team has rescued more than 40 dogs over the years, and we try to help where we can, especially where there is a danger that owners may get into difficulty trying to sort things out themselves.
"Many of the team have their own dogs, and fully empathised with what the owners must have been going through. All the volunteers had made themselves available in full knowledge that this was a seach for a dog. Such incidents also provide us with excellent training for crag search and rescue."