Need to know—because ignorance ain’t bliss.

By Tim Neville | Photo by Ian Shive

El Cap, in Yosemite National Park, is one of the most photographed and climbed rocks in the world, but the Chief still holds a few surprises. Here’s what you may not know about America’s greatest big wall.

A lonely 80-foot-high ponderosa—the El Cap tree—somehow clings to the granite just below the North America Wall about 400 feet (or four pitches) up the face. It’s the only big tree on the face of the monolith.

Despite the sheer, seemingly inhospitable terrain, the cracks and ledges are an ecosystem. Mice scurry up cracks as snakes pursue them. Pacific tree frogs use their sticky pads to hop around on the vertical granite and live deep in fissures where moisture collects. “I’ve never seen one take a fall,” says Ken Yager of the Yosemite Climbing Association.

In 1986, guidebook author Don Reid and Yager were climbing the Salathé Wall when their bivy site was overrun with wingless insects called silverfish. “You just had to sleep with them crawling all over you,” says Yager. “It was itchy.”

Ansel Adams took his first picture of El Capitán in 1916 when he was 14 years old. He took his last well-known photograph of it—El Capitan, Winter, Sunrise—in 1968.

Twenty-three people died climbing El Capitán between 1955 and 2012. Twelve of those deaths occurred on The Nose.

To a climber, El Cap looks like delicious granite. To University of North Carolina geologist Roger Putnam, who recently completed the first rock composition map of the face, it looks like eight granites. El Cap granite—73 percent silica—covers the bottom two-thirds of the face. The rock that lends itself to the magnificent cracks and world-class dihedrals of routes like New Dawn and The Shield is Taft granite, which is 76 percent silica and therefore harder. El Cap’s worst granite? The Diorite of the southeast facing North America Wall. Only 50 percent silica, “It’s brittle garbage,” says Putnam.

In October 2010, a rockfall the size of 14 school buses let go. In El Cap Meadow you can see remnants of a 3,600-year-old rock fall that was more than double that size.

In the 1990s, a climber was using his body mass and pulleys to counterweight two haul bags up El Cap—a common technique. One bag was heavy with survival gear. The other was light with beer cans. Somehow he confused the two and when he applied all of his body weight to lift the bag of empties, he rocketed down the face, the bag shooting skyward. The climber, who had not tied into the rope properly, ended up tangled in his lines and dangling by a leg. “He was very lucky,” says Yager.

Biggest vertical gain: 2,900 feet, 31 pitches, The Nose.

Number of routes: About 70.

First ascent: After 47 days of climbing over 18 months, by Warren Harding, Wayne Merry, and George Whitmore on November 12, 1958.

Fastest ascent: Two hours, 23 minutes, 46 seconds by Alex Honnold and Hans Florine, on June 17, 2012.

Surface area: About 370 acres or half a square mile.

Age of rock: About 100 million years.

Time it took for those rocks to form: 2.7 million years.

How far down those rocks used to be before uplifting and erosion exposed them: 2.5 to 9 miles deep.

From the Spring 2013 issue.