Emily Harrington climbs the Golden Gate route of Yosemite's El Capitan in one day

Emily Harrington was close to the 3,000-foot top of Yosemite National Park's El Capitan, close to achieving the historic goal she'd spent years working up to, and she was resigning herself to the idea that it was out of reach — again.

Just like last year, when she almost reached that point but, exhausted, just couldn't clinch it. Or a few weeks after that, when she slipped and fell only 150 feet up from the ground, ropes catching her but leaving a wicked rope burn on her neck that took her out for the season.

Again, she took a fall. Again, she was there, hanging off the side of El Cap, bleeding, with a gash above her eye.

"There was a part of me that didn't want to climb again," she told ABC News. "I was so emotionally drained and exhausted, and there was a part of me that wanted to give up and just be like, 'This is it; this is done. It's not for me.'"

But there, hanging off the side of the park's iconic granite wall, her team checked out the puncture wound — they could patch it up. They ran through concussion protocol — no signs. All she had to do was get herself to keep climbing.

"I had to go through the process of convincing myself that I had earned the right to try again up there and I had worked so hard and I deserve to try again," Harrington said. "It was like I hit rock bottom and clawed my way out."

After that, there was just one more difficult pitch — what climbers call portions of a climb — to get through before it was smooth sailing to the top. It was after sunset, and she'd been climbing for 18 hours. That one last difficult pitch she was facing down was the one she'd bailed on last year. It was dark, she had a headlamp on, and she willed herself to just try it.

"It was one of the moments that you kind of live for in climbing, when you just execute something so perfectly," she said. She finished that portion "flawlessly," and "that's when I knew I was going to do it. And it was a really, really powerful feeling."

There were, she said, "a lot of tears."

After 21 hours and 13 minutes of climbing, Harrington reached the top. In doing so, she became the first woman — and fourth person of any gender — to free-climb the Golden Gate route of El Capitan in one day. She is now the fourth woman to free-climb El Capitan in a day on any route. "Free-climbing" means you're attached to ropes, so if you fall, you're caught, but the ropes do not assist the climb.

"[Climbing] still is very much a world where men kind of dominate," she told ABC News, "and I think for me it took a long time to realize that I did belong up there and that I didn't have to do it the way everyone else said I had to do it. There's no formula and I did it my own way."

It's an extraordinary feat that requires not just technical climbing skill, not just power, but also mental and physical stamina.

After the two failed attempts last year, Harrington spent 12 months working on those factors, building up strength and power through bouldering and building up stamina through runs in the mountains around Lake Tahoe, where she lives with boyfriend Adrian Ballinger, a mountaineer who followed her through the training and attempts. She worked on climbing efficiency, looking at where she could move smarter to climb not more quickly, but with less energy.

It wasn't always clear she was going to be able to make an attempt this year: The coronavirus pandemic shut down Yosemite National Park in the spring, and in the fall, it shut down due to wildfires.

The pandemic, Harrington said, did have one "silver lining" as it allowed her to stay focused on her goal, with travel and other distractions cut off.

She did, she said, have some anxiety and fear going back to the wall after her fall last year — which caused a media frenzy.

But for one thing, she knew she had the training, and for another, she knew exactly what had gone wrong (she and Alex Honnold, of "Free Solo" fame, who has been her partner on El Capitan, didn't use enough gear for the ropes, she said, and they climbed on a cold day), so she knew how to avoid it.

Harrington first completed a climb of the Golden Gate route of El Capitan in 2015, over six days. Two years ago, she began seriously training to do it in under a day.

But, she said, it feels more like "a life goal" than something she's been working toward for years.

"In a way this was my life's dream," she said. "This is the culmination of everything I've ever put into my climbing all summed up in one day."

Editor's note: The headline of this story has been updated for specificity.