Police said the pair were on a day walk on Friday when they ventured into the hills and missed a track turn. They went past their turnaround point and became lost.
South Canterbury and Rakaia Land Search and Rescue volunteers, including Goose the dog, and the Aoraki police SAR squad searched for the overdue walkers for several hours in the dark.
But it was Goose and his handler who picked up their scent and found strong signs leading them along the ridge above Little Mt Peel towards Mount Peel.
The helicopter found the missing walkers, who were huddled in the scrub near the summit of Middle Mount Peel, shortly after Goose narrowed down the search area.
They were both airlifted off the mountain about 3.30am, seven hours after being reported missing.
They were assessed by the Westpac crew and one of the walkers was taken to hospital for further medical attention.
"It is a timely reminder to ensure when venturing out into the hills to be fully prepared, and to check the forecast," a police spokesperson said.
"Weather conditions can change quickly and although it may be fine when you start your walk you must be prepared for the cold and dark.
"Ensure you have working communication equipment and if you are relying on your cell phone for all manner of navigation and communication, take a battery pack and make sure you know how to use it.
"We’re grateful to everyone who’s contributed to this successful outcome."