Half Dome

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Half Dome is a granite dome at the eastern end of Yosemite Valley, possibly the Valley's most familiar sight. The granite crest rises more than 1,440 metres (4,737 feet; 0.897 miles) above the Valley floor.

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As late as the 1870s, Half Dome was considered completely unclimbable, but it may now be ascended in several different ways. Thousands of hikers reach the top each year by following a trail from the valley floor. The trailhead is only two miles from Half Dome itself, but the circuitous route is 8.5 miles (13.5 kilometres) long. The final ascent is accomplished by following a pair of metal cables raised on posts up the peak's steep but somewhat rounded east face. The cable route was constructed in 1919.

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Alternatively, over a dozen rock climbing routes lead from the valley up Half Dome's vertical northwest face. Other routes ascend the south face and the west shoulder. The first route climbed was the Regular Northwest Face route - originally climbed in 1957 by Royal Robbins, Mike Sherrick, and Jerry Gallwas. This 5-day ascent was the first Grade VI climb in the United States.

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Half Dome is an excellent example of an exfoliation dome. Half Dome probably was never a complete, round dome. When Half Dome formed, there were fractures in the granite. Water inside the fractures froze and thawed repeatedly. Glaciers eroded the base of the dome. Finally, about 20% of the dome fell and was carried away by the Tenaya glacier, leaving an almost-vertical cliff.

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An image of Half Dome, along with John Muir and the California Condor, appears on the California State quarter, released in January, 2005.

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Half Dome was originally called "Tis-sa-ack," meaning Cleft Rock in the dialect of the local Native Americans. Tis-sa-ack is also the name of the fourth route on the formation, ascended by Royal Robbins and Don Peterson over eight days in October, 1969.

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Granite dome: A granite dome is a dome of granite, formed by exfoliation....

Yosemite Valley: Yosemite Valley is a world-famous scenic location in the Sierra Nevada of California. It is the centerpiece of Yosemite National Park....

Granite: Granite is a common and widely-occurring group of intrusive felsic igneous rocks that form at great depths and pressures under continents. Granite consists of orthoclase and plagioclase feldspars, quartz, hornblende, biotite, muscovite and minor accessory minerals such as magnetite, garnet, zircon a...

Half Dome related Images and Photos (experimental)

Half Dome and Elm	Half Dome Merced River Winter	Half Dome Winter Sunset Yosemite	Half Dome from Glacier Point
Half Dome Yosemite National Park California	Half Dome And Yosemite Valley From Glacier Point	Half Dome Mountain in Yosemite National Park California USA	Moon and Half Dome Yosemite National Park 1960
Half Dome Above River and Winter Snow Yosemite National Park California USA	Half	Dome	Half Moon