2 Attempt 'Hardest Rock Climb in World' Climbers more than halfway along El Capitan's Dawn Wall in Yosemite By Matt Cantor, Newser User Posted Jan 5, 2015 12:18 PM CST 9 comments Comments This April 2013 image shows three of Yosemite's best-known attractions: The El Capitan summit on the left, the granite peak known as Half Dome in the distant center, and Bridalveil Fall on the right. (AP Photo/Kathy Matheson) (Newser) – Two climbers in Yosemite National Park are attempting a feat no one has ever accomplished: climbing the entirety of a smooth rock face known as the Dawn Wall, part of the El Capitan formation, while shunning ropes except to catch their falls. Tommy Caldwell and Kevin Jorgeson have already passed the halfway point in their effort, National Geographic reports. "It’s going great up here! Spirits are good and we’re feeling optimistic. It’s been a rad adventure, for sure," Caldwell says. "But we still have a lot left to do." If they manage it, "it will be the hardest completed rock climb in the world," another climber tells the New York Times. "This will be the climb of the first half of the 21st century." The journey to the top offers little to grip, and at one point, climbers must jump sideways—off the rock face—to grab "holds the size of matchsticks," John Branch writes in the Times. A previous attempt was prevented by storms, but this time, "the weather is working out great," Caldwell says. The two have been practicing for years, working on individual sections of the wall before trying them all in one go. After starting the latest effort in December, they've passed a section known as the 14th pitch, thought to be the hardest. Now, the "best case is seven days" to finish the mission, Caldwell says. “Worst case is mid-February. Or not at all, I suppose."