For the first time ever, two men, 30-year-old Kevin Jorgeson and 36-year-old Tommy Caldwell, will ascend one of the world's largest and most difficult cliff-climbing routes in the world using only their hands and feet.
They are climbing El Capitan, a 3,000-foot-tall granite monolith in Yosemite National Park in California. This monolith has been climbed many times before, but they are ascending the Dawn Wall route, a sheer face of rock considered by many to be the longest and hardest free climb in the world.
Jorgeson and Caldwell are climbing with ropes, but these are used to protect them from falls, not as climbing aids. The razor-sharp holds on the rock wall tend to cut their fingers, so they spend occasional rest days in their tents, suspending them hundreds of feet up as they let their fingers heal.
Kevin Jorgeson and Tommy Caldwell are climbing a sheer 3,000-foot wall of granite on El Capitan in Yosemite
They are already almost half-way up, and they are sharing their journey with the world through Twitter and Facebook
It is considered by many to be the hardest climb in the world
In some places, they have nothing more than their finger-tips to hold them
They've had to tape and glue their fingers to help them heal from the wall's razor-thin hand holds
They will be the first people ever to ascend this legendary route by free-climbing
They prefer climbing at dusk, when it's too cold for their palms to sweat
The ropes these climbers use only serve as safety equipment - they do not help them climb
A supporting team has dropped them provisions and they use solar power for their devices
They've been climbing for 10 days and think they have about a week left. Be sure to follow their historic ascent on Facebook or Twitter!
Photos by Big UP Productions and Tom Evens