On June 3, 2017, as seen in the Oscar-winning documentary Free Solo, Alex Honnold achieved what most had written off as unattainable: a 3,000-foot vertical climb of El Capitan in Yosemite National Park, without a rope or harness. At the time, only a few knew what he was attempting to do, but after topping out at 9:28 am, having spent just under four hours on this historic feat, author Mark Synnott broke the story for National Geographic and the world...