Two rock climbers just free climbed El Capitan’s Dawn Wall for the first time

On Wednesday evening, two mountain climbers — Tommy Caldwell and Kevin Jorgeson — completed a 19-day-long ascent of the Dawn Wall of the El Capitan rock formation in Yosemite National Park.

In succeeding, they became the first people to ever free climb the 3,000 foot route — considered by many climbing experts to be one of the most difficult climbs in the world.

Free climbing means that ropes and other equipment are used to protect against falls, but can’t be used to help the climbers move upward. There are nearly 100 different routes up El Capitan, but Caldwell and Jorgeson specifically chose to attempt the Dawn Wall, an extremely smooth granite rock face, that, in some places, has razor-sharp finger holds as small as pebbles.

This year, they began on December 27, so that cold temperatures would limit sweat and allow them to grip the rock more easily. They also climbed at night, with headlamps, so the sun doesn’t heat the rock.

The pair have set up a hanging tent about one-third of the way up the wall. After each night’s climb, they used ropes to descend down to it, slept, ate, and then hoisted themselves back up to the spot each left off at previously.

The climb is made up of 32 pitches — sections of the route that are roughly equal in length to a single climbing rope. During training, Caldwell and Jorgeson successfully climbed each pitch in isolation (that is, getting hoisted to the beginning of it), but this was the first time they — or anyone — free climbed all 32 pitches in succession.

Further reading: Explore the New York Times’ interactive map of the Dawn Wall