Libby Riddles won the Iditarod in 1985, and then Susan Butcher won it 4 of the next 5 years. So it would be quite fair to say that in the late 1980's women were the world's top mushers.
One could argue I suppose that the dogs have the most athletic part of that sport. However, surviving and doing anything productive in an Alaskan blizzard is more than athletic enough for me, and the dogs (particularly lead dogs) themselves are often as not also female.