Rescue workers carry Donna Molnar into a rescue vehicle Monday after her dog found her three days after she was buried under snow in a field near the Hamilton, Ont., airport. (Courtesy CHCH)

A missing Ontario woman was found alive Monday afternoon, after spending three days buried under deep snow in an isolated field near the airport in Hamilton.

Hamilton police, who spent Saturday, Sunday and Monday searching for the 55-year-old Ancaster secretary, said it is nothing short of a miracle that she survived in what police describe as "horrific" weather conditions.

"The word miracle was used several times, given the circumstances," Insp. Bob Buck told CBC News on Monday.

"[By Monday], we thought we were in search and recovery mode. We were still optimistic, but we were quite surprised to find her."

Buck said the woman, a mother of one who works for the local Catholic school board, left her home on Friday to go for a walk, as she often does. She usually drives to a quiet location, parks her SUV, and explores the area on foot.

When she didn't come home Friday afternoon, her husband called police. By that time, weather conditions were "horrific" Buck said, with heavy winds, blowing snow and cold temperatures.

On Saturday afternoon, officers found the woman's SUV off Fiddler's Green Road and launched a full-scale search. About 20 police officers and trained volunteers searched the area with the help of all-terrain vehicles, snowmobiles and police search dogs.

Search dog paws at snow

The search team covered several square kilometres, but it wasn't until 12:30 p.m. ET on Monday that a police dog named Ace started pawing at the snow near a pond. The dog and his handler, Ray Lau, dug through the snow and pulled the woman out.

"She was covered in snow, you wouldn't even be able to see her because of blowing and drifting snow," Buck said.

The woman was able to speak, but suffering from hypothermia. She is now recovering in hospital, although police do not have an update on her condition.

Police didn't release her name, but she has been identified in media reports as Donna Molnar.