The couple, both in their 20s, called for help at about 2 p.m. PT when they became lost in Lynn Headwaters Regional Park.
The North Shore Rescue Team and Talon helicopters lifted the couple out with a long line from after they got trapped on a cliff face in a rugged area of the park called "the Needles."
Search manager Tim Jones says the pair was lucky they were carrying a cellphone to call for help, but the phone's co-ordinates weren't exact.
Jones says it was one of the toughest rescues he's done all year: the light was dwindling; fog was setting in, and the helicopter was running out of fuel.
With temperatures dropping, the couple was wearing only light clothing and had no other supplies.
"If it hadn't been for cell coverage, they would have been in serious, serious, serious trouble."
The young couple received a stern lecture, but otherwise emerged unscathed from the backcountry trek.
But Jones says the incident could have been tragic because the young woman was already mildly hypothermic and the man's condition was not much better.
"They would have been at the very least severely hypothermic tonight. And probably by morning the female would have expired. That's how close it was for these people."
Jones said the couple is from Ontario, didn't know the area and hadn't told anyone where they were going.