Wearing only her Clarks shoes, she fell numerous times in the chilled mud.
According to The Des Moines Register, she fell face first in the mud and had to wait two hours before having enough strength to get to her feet.
After falling a second time, Harnish chose to return to her vehicle.
"I knew getting back to the car was my best bet. If I was going to be rescued at all, I would need to be in the car," Harnish told the Register.
After removing mud and debris from her keys, she spent the next few days starting and stopping her car to keep warm.
Over those days, Harnish said that she snacked on marzipan cake and drank two bottles of kombucha, the only food she had with her.
The rental car finally ran out of gas Sunday morning, right before a blizzard began.
On Sunday evening, teenagers on snowmobiles spotted Harnish when she honked her horn and flashed her lights to get their attention.
"They opened the door and screamed 'Oh my God, she's alive! Thank God for a miracle." she told the Register.
She suffered no serious injuries and was released from an area hospital.
Harnish is from Hubbards, Nova Scotia, and is well known in her community. She is also a professional storyteller and operates Terry Tales International.