SAN FRANCISCO (AP) - Two men are roughly halfway through what has been called the hardest rock climb in the world: a free climb of a half-mile section of exposed granite in California's Yosemite National Park.

Tom Evans, a climber and photographer, has been chronicling Kevin Jorgeson, 30, of Santa Rosa, Calif., and Tommy Caldwell, 36, of Estes Park, Colo., as they scale their way using only their hands and feet.

El Capitan, the largest monolith of granite in the world, rises more than 3,000 feet above the Yosemite Valley floor.

The men eat, stretch and sleep in hanging tents suspended to El Capitan's Dawn Wall. They don't have the creature comforts of home, but they have kept in touch with the outside world thanks to social media - tweeting, posting on Facebook, feeding information for blogs and keeping in touch with a bevy of supporters on the ground.

"The guys are doing great," said Josh Lowell with Big Up Productions, which has been chronicling their climbs for the last six years. "(Monday) they are resting and trying to grow skin back on their fingertips so they can continue to do battle with the hardest climbing sections, which involve grabbing tiny, razor-sharp edges of rock," Lowell said.

If all goes as planned, the duo could be at the top as soon as Friday or Saturday, Lowell said.