Yosemite has more domes than any other place on the planet. It's most famous, Half Dome can be seen from Yosemite Valley and Glacier Point inside the park. It is 8,800 feet of towering granite and a world-renowned icon of Yosemite National Park.

The domes were formed about 65 million years ago, when molten, igneous rock solidified into granite deep within the Earth and was pushed up under pressure to the surface. The granite was shaped into domes as the uplifted, curved layers of rock cleaved off.

Half Dome’s “Missing” Half

Despite its misleading name, Half Dome was never whole. Millions of years ago, Half Dome was larger than it is today, but it never sported a matching half in front of the sheer cliff face. Deep inside the great hunk of rock, a broad vertical crack was exposed when glaciers flowed by and undercut Half Dome’s base. The glaciers carried away about 20 percent of the formation (geology buffs like to joke that it was originally an 80-percent dome); more blocks of rocks cleaved away from the crack over time, leaving the sheer face that park visitors see today.

Half Dome Facts

Half Dome Elevation: 8,842 feet (2,650 meters)

Total Elevation Gain: 4,800 feet (1,600 meters) from Yosemite Valley

Best Time to View: Early season when the waterfalls are at their fullest from snowmelt.

Hiking the Half Dome is a 14-16-mile round trip and takes about 10-12 hours. There are cables along the last 400 feet of the climb to the summit and the cables and unsafe in inclement weather and if not used with care. Permits are required to climb Half Dome.

Related Stories: Half Dome Hiking Survial Guide | Forming Yosemite's Granite Domes | Permits Make Half Dome Safer