Two rock climbers are about to make world history as they free climb Yosemite's El Capitan in Yosemite National Park, Calif. 

Tommy Caldwell, of Colorado, and Kevin Jorgeson, of California, are using nothing more thant their hands and feet to clime the 3,000-foot sheer piece of stone. All they are using to prevent deadly falls are ropes and harnesses, reported The Associated Press. 

One of the biggest obsticles of climing El Captain is how few grooves there are to grab on to. 

"They're pushing the limits of our sport beyond what most people can even fathom," Julie Ellison, senior editor of Climbing magazine, told The State - a South Carolina-based news site. 

They are approaching the top after 17 days of climbing so far, but it's been a challenging feat for the men who both trained for more than five years before this historic climb, reported AP.

Jorgeson alone fell 11 times over a seven day stretch while trying to get past one tough section of the climb.

El Capitan is the largest granite monolith in the world, with about 100 routes to the top, reported AP. The first climber reached the summit of El Captian in 1958. 

The climbers are expected to reach the top today.