Two men are  halfway up what has been called the hardest rock climb in the world - a free climb up a half-mile section of exposed granite in California's Yosemite National Park. Tommy Caldwell, 36, of Estes Park, Colorado, and Keven Jorgeson, 30, of Santa Rosa, California, have been scaling their way up the face of the 3,000 feet granite monolith of El Capitan in Yosemite using only their hands and feet. Most ascents up the imposing rock face use an approach known as aid climbing, where ropes and metal pins are used to assist the climbers. Don't look down: Jorgeson calculates his next move up the mountain in this photo posted on Instagram on Sunday
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Climbers Kevin Jorgeson, 30, and Tommy Caldwell, 36, are making their way up El Capitan - the largest monolith of granite in the world - in a single push without pulling on any  equipment to aid their ascent
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Many have climbed El Capitan before, but if successful, the pair would be the first to 'free climb' a route known as the Dawn Wall in what is considered to be the most difficult multipitch climb in the world
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Caldwell is doing the climb despite cutting off much of the index finger of his left hand in a DIY accident with a saw
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Razor sharp holds on the rock have taken their toll on the pair and they are now climbing with their fingertips taped
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Free climbing involves using ropes and clips to protect in case of a fall, but does not aid the actual ascent
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Jorgeson and Caldwell hope to reach the summit of El Capitan as by Friday or Saturday to end a six year project
Live from El Capitan: On Friday, @placeholder hosted a question and  answer session from the wall.