Helen Thayer

What does it take to be named One of the Greatest Explorers of the Twentieth Century by National Geographic Magazine? Helen Thayer knows.

She walked across the Sahara and Gobi Deserts for a total tally of more than 6,000 sandy miles. She kayaked more than 2,000 miles down the Amazon. She traveled the Canadian polar sea to study wild wolves for a year, living right next to a wolf den for half of that time. At the age of fifty, she pushed her own sled to the magnetic North Pole accompanied only by her polar bear dog, Charlie. And when she's not doing something else, she'll climb a mountain.

In-your-face women, it seems, rarely sit still.