"It was a beautiful walk.
"The landscape around here is stunning, and we have had a lovely time," Miss Clark said, as she was walked towards the shelter at the end of the track.
Miss Clark's group included husband Peter Davis, sister Sandra Clark, Labour MPs Darren Hughes and Chris Carter and Mr Carter's partner, Peter Kaiser.
They were part of a 24-person group on a guided walk with the Queenstown-based company Ultimate Hikes.
As a keen tramper, skier and mountaineer, Miss Clark said she had done many walks, but this was her first time on the Routeburn.
After a couple of mostly dry days, the group had walked through rain on their final day.
Despite the showers, the group was in good spirits, exchanging farewell hugs with the guides and fellow walkers as they reached the sign indicating the end of their walk.
Miss Clark's party will be flying from Queenstown to Auckland today, and she will be flying back to her New York base on Sunday.
"Even with just an evening and morning available, it is always a pleasure to visit Queenstown.
"The last time I was here was back in August, where I managed to fit in some great alpine and cross-country skiing," she said.
She said this visit was her third trip back to New Zealand since she took up her position as head of the United Nations Development Programme in New York.
There will be a lot of travelling in the future, as Mr Davis has kept his job at Auckland University.
"Someone has to look after our home in Auckland," she said.
"We will just have to keep travelling back and forth as we have done for years."
Despite the long-distance marriage, she said she was settling in to her new job and life in New York very well.
"I'm absolutely loving it.
"It is actually not all that different from my previous role.
"It's all politics."
Miss Clark was awarded the Order of New Zealand on New Year's Day.
She said she was pleased with the honour, but stressed that it did not carry the title "Dame".
"If it did, I would not have accepted it," she said.
