Intrigued about this unknown Kiwi hero, I wanted to find out more. Asking around, I realised no one else had heard of her either. A friend's mum was vaguely aware of her, remembering that she competed in discus in the 1962 Perth Commonwealth Games. Yes, Thayer was an athlete too, and in her lifetime has represented NZ, Guatemala and the United States in international track and field.
Perhaps that's the problem.
Thayer left New Zealand in 1961 after marrying American helicopter pilot Bill, first living in Guatemala and Honduras, before settling in the US. Pictured right, she's waving a US flag at the North Pole. But, interviewed via email from her home at the foothills of Seattle's Cascade Mountains, Thayer assured me she is still very much a New Zealander.
"I will always be a Kiwi and intensely proud of it," she writes. "I have travelled, so far, to 36 countries and have decided that there is no better country in the world than our own.
"The New Zealand press never expressed interest in my expeditions or my educational programmes. Perhaps it was because I was married and lived overseas."
Thayer (right) left New Zealand in 1961 after marrying American helicopter pilot Bill. Photo / Helen Thayer
It seems incredulous that we as New Zealanders don't celebrate Thayer's each and every achievement. Keith Urban hasn't lived in the country since his late teens, but we're proud to call him a Kiwi. Russell Crowe left New Zealand aged 4 and yet we still claim him as our own, even in his biggest moments of boorish Aussieness. So why have we rejected Thayer?
Growing up on a farm in Whitford, near Howick, Thayer's childhood was "very outdoorsy". She had "great parents" who inspired her love of adventure. Another major influence in her life was family friend Ed.
That's Sir Edmund Hillary to the rest of us.
Helen Thayer in the Sahara. Photo / Helen Thayer
"He was one of my childhood mentors. He was a truly kind and generous man."
At the age of 9, Thayer climbed Mt Taranaki with her parents and Hillary. She cites this as the moment she realised her future was in adventure and expedition.
"I was fascinated by mountains and knew that I would have to climb and adventure overseas. My parents and Ed inspired me, but I think it was already stamped in my genes from birth."
As she excelled in her athletics career, she realised competing against others wasn't her main driver. She was more interested in achieving personal goals. She went back to mountain climbing and, aged 50, became the first woman to travel solo to the Magnetic North Pole.
Kiwi explorer Helen Thayer and husband Bill walking in the North Pole. Photo / Helen Thayer
"It was very difficult," she writes. "I was a pioneer for women in polar travel on foot and ski. There was no equipment available and little information. That made the challenge all the more worthwhile.
"Polar bears were a constant threat and to be alone among them on foot was a formidable challenge. However, I am very happy I made the journey. It opened up a whole new world of writing, public speaking and many other expeditions."
These have included walking across the Sahara along a 6440km trade route from Morocco to the Nile River; walking 2575km across the Mongolian Gobi Desert; becoming the first non-indigenous woman to kayak 3540km along the Amazon River; living alongside a wolf den for more than six months in the Yukon; and together with Bill, becoming the first couple to travel unsupported to the Magnetic North Pole.
Now 79 and 89, they are still adventuring together. Two years ago they walked 1448km across the Sahara, trekking with the Berber tribe. For her next adventure, she wants to walk across Australia's deserts.
Kiwi explorer Helen Thayer with Maasai women. She has travelled to 36 countries. Photo / Helen Thayer
"I am still a work in progress with no plans to retire," she writes. "We are what we think we are. I think I'm still 38 going on 39. I still have many more hundreds of miles to walk and mountains to climb. And more programmes to produce for Adventure Classroom."
The latter, a not-for-profit organisation she and Bill founded, educates and inspires students to explore the world and "embrace integrity, demonstrate courage, and assume responsibility for their actions".
She has shared her experiences with more than one million students, and she and Bill continue to develop their programmes.
Helen Thayer, pictured at the North Pole, counts Sir Edmund Hillary as a childhood mentor. Photo / Helen Thayer
Travel has provided "the ability to motivate audiences of all ages". But as time and age advance, why does Thayer continue to travel?
In the humble words of a true Kiwi, she concludes, "I like to see what's on the other side of the hill."
HELEN THAYER'S TOP TIPS FOR FEMALE ADVENTURE TRAVEL
Don't take on challenges just because you are a woman and think you have to prove anything.
2. Women can do anything they set their mind to, the main thing is to think out of the box and meet challenges head on.
3. A goal without a plan is only a dream.
4. Age is no barrier to your dreams and goals.
5. Don't listen to negative comments, such as the "polar bears will eat you", "you will fall in the ocean and drown", "Amazon snakes will kill you", "you will die of thirst in the desert". There is a long list of comments. As long as your goal is important to you, you plan thoroughly before leaving, go ahead and be confident. Believe in yourself.