In Nature's Altars: Mountains, Gender, and American Environmentalism,Susan Shrepfer reveals how in the early 20th century the mountains became a sanctuary for what was briefly known as "The New Woman." Unfettered from womanly duties and heavy skirts, these women found a freedom distinct from their urban sisters, the flappers, and arguably more meaningful. Writes Schrepfer:
The majority of women climbers...wrote of deliberately seeking mountains because they were places where they might escape artificial encumbrances, walk as equals of men, and dress comfortably. This implies that women who climbed saw clothes as signifying confinement, subordination, and discomfort. Mountains were places in which to act "the fair barbarian," to indulge "Bohemian tastes," to "redefine the concept of necessities, and to trim skirts." The growing acceptance of athleticism helped such women redefine their feminiity. According to historian Sarah A. Gordon, "The novelty and marginality of clothing for sports provided a space in which women contested notions of "feminine" and "appropriate" bodies, behavior, and appearances. The "new physical culture" of sports "infused and informed the emerging concepts of the New Woman."
The New Woman apparently faded away with the onslaught of World War II. Now, of course, women can do whatever they wish in the wilds. Heck, a nine year old girl completed the Pacific Crest Trail in 2012.
"Monkey" is the older kid: she completed the Muir Trail at age seven.