The Yosemite Big Wall permit program now requires climbers to register on its most popular walls. Climber reactions are predictably mixed. Emily Harrington, a 34-year-old Yosmeite pro, becomes the ...

LLNL announces a new tsunami warning system using the world's fastest supercomputer, El Capitan, for real-time forecasts.

The El Capitan Theatre was buzzing as D23 fans got an exclusive first look at "Alien: Earth" during a special early screening ...

After becoming the youngest person to climb El Capitan in Yosemite by rope, 11-year-old Sam Evermore is now also the youngest American to climb the Matterhorn in the Alps. David Muir shares his story.