Rock climber scaled Yosemite's El Captain

Finally tonight here, America Strong, the climber, the mountain, and the girlfriend holding a breath. The famed El Capitan, a 3,200 foot wall of granite in Yosemite. It's nearly impossible to scale with safety equipment, let alone with none. That young man in a red shirt, that's Alex Honnold of Sacramento. You met him right here before. He has been perfecting that climb without a rope for a decade. He uses only his bare hands and his feet to ascend. In just three hours, 56 minutes, he became the first person ever to free solo El Capitan. At the time, he told us what he was thinking during the climb. I looked down, you know, from time to time, enjoyed the view. I was mostly looking up. I was pretty excited and I was charging pretty quickly and I was just kind of climbing ahead. The story of Alex's historic climb was filmed for more than two years by National Geographic, following him on his journey, how he did it, and those around him who supported him. We meet his girlfriend, Sonny. What if something happens? What if I don't see him again? Alex now telling Nightline what he sees when he looks back. I knew exactly what I was doing and I was very excited to be climbing. I was having this beautiful experience and I felt like I was climbing well and, you know, doing exactly what I love to do on the most beautiful wall on earth. I mean, it was glorious. Just incredible. The documentary Free Solo opens in theaters Friday. I'm David Muir. I hope to see you for our coverage of the Kavanaugh hearing tomorrow morning and right back here tomorrow night. Good night. Hi, everyone. George Stephanopoulos here. Thanks for checking out the ABC News YouTube channel. If you'd like to get more videos, show highlights and watch live event coverage, click on the right over here to subscribe to our channel. And don't forget to download the ABC News app for breaking news alerts. Thanks for watching.