Sibylle Hechtel’s first climb was on the crumbling limestone walls of southern Germany with her father, at age three. Her dad, rocket scientist and prolific climber Richard Hechtel, made the first ascent of the 4,500-meter Peuterey ridge on Mont Blanc in 1953. It was the longest and most difficult route in the Alps at the time and a climb he would later free solo. She was eager to follow in his footsteps.

The Hechtels moved to southern California when Sibylle was eight. During college, she spent summers in the park, climbing anything and everything. In 1973, she made two significant first ascents: the first all-women’s big-wall climb up 1,100-foot Washington Column, with Anne Marie Rizzi, and the first all-women’s ascent of 3,000-foot El Capitan, with the late Beverly Johnson.

Hechtel completed her education in the mid-80s, earning a Ph.D in Biology. But after working for a few years as a science writer, she burned out and quit. Soon after, she began expeditioning in the world’s great ranges, including the Himalayas, where she attempted Mount Everest in 1988. Her one son, Tristan, came along in 1990, and four years later, she did her final Himalayan expedition, to 8,027-meter Shishapangma in Tibet. Today, somewhere in her 60s (we think: she won’t reveal her age), she still takes frequent climbing trips to Colorado’s Eldorado Canyon; Indian Creek, Utah; Squamish, British Columbia; limestone walls in Spain and Italy; and even El Capitan. She talked to us about her life while pulling weeds at her home in Boulder, Colorado.

Tell us about your adventurous upbringing.

I’ve always been mentally solid because my father had me climbing all this weird stuff at a young age. That’s probably my saving grace in terms of not being afraid. I was in an avalanche when I was seven. After getting buried, we had to do a river crossing and one of the women in our group broke her leg. Those were the kind of trips my father took me on. I think he took my family and friends places that he probably shouldn’t have.

You’d live for months each summer in Yosemite. How did you sustain yourself?

I had 10 bucks a month for food and I scrounged leftovers every breakfast and dinner at the park cafeteria. Even today, my immediate urge is to grab food off someone’s plate at a restaurant before it gets taken away.

What did you think of your first big walls? 

I liked them from the beginning. I loved the views and the scenery and the quiet. I didn’t mind sleeping on ledges. I started sleeping on them when I was a teenager.

Why did you leave science?

I got my Ph.D at UC Irvine, then took a job as a postdoc in Ann Arbor, Michigan. I didn’t realize how much work was needed in academics—more than 70 to 80 hours a week. After four years, I decided I could do something better with my life. I like science. I think the research is interesting. I don’t like working seven days a week.

What happened on Shishapangma? 

We were too early and the weather was too unstable, so we didn’t summit. One night our tent pole broke under 80-90 mph winds and falling snow. It took me years to get over that night spent pushing against the tent walls to keep from suffocating. The next day, I slipped during the descent and began cartwheeling down the face before stopping on a small pile of snow. If I had cartwheeled any father, I’d be be dead. That was the end of Himalayan expeditions, Canadian mountaineering, and mixed and ice climbing, because I had a three-year-old at home. Shishapangma taught me fear. I learned humility. I learned that I wasn’t invincible.

After becoming aware of your own mortality, were you scared when you went back on El Cap in 2014?

I didn’t feel scared on El Cap. It was great to be back to one of my favorite places. I felt at home.