Half Dome

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Half Dome

Half Dome from Yosemite Valley
Elevation 8,836 ft (2,693 m)
Location Mariposa County, California, USA
Range Sierra Nevada
Prominence 1,360 ft (415 m)
Parent peak Clouds Rest [1]
Coordinates 37°44′45.6″N 119°31′59.4″W / 37.746°N 119.533167°W / 37.746; -119.533167
Topo map USGS Half Dome
Type Granite dome
Age of rock Cretaceous, 93 Myr
First ascent 1875 by George G. Anderson
Easiest route cable route

Half Dome is a granite dome in Yosemite National Park, located in northeastern Mariposa County, California, at the eastern end of Yosemite Valley — possibly Yosemite's most familiar sight. The granite crest rises more than 4,737 ft (1,444 m) above the valley floor.

Contents

[edit] Ascents

As late as the 1870s, Half Dome was declared "perfectly inaccessible".[2] The summit was finally conquered by George Anderson in October, 1875, via a route constructed by drilling and placing iron eyebolts into the smooth granite.[3]

Today, Half Dome may now be ascended in several different ways. Thousands of hikers reach the top each year by following an 8.5 mi (13.7 km) trail from the valley floor. After a gradual 2 mi (3.2 km) approach, the final pitch up the peak's steep but somewhat rounded east face is ascended with the aid of a pair of post-mounted braided steel cables originally constructed close to the Anderson route in 1919.

Alternatively, over a dozen rock climbing routes lead from the valley up Half Dome's vertical northwest face. The first technical ascent was in 1957 via a route pioneered by Royal Robbins, Mike Sherrick, and Jerry Gallwas today known as the Regular Northwest Face. Their 5-day epic was the first Grade VI climb in the United States.[4] Other technical routes ascend the south face and the west shoulder.

[edit] Geology

Half Dome, showing the valley and surrounding area.

Half Dome is nearly as whole as it ever was. The impression from the valley floor that this is a round dome which has lost its northwest half is an illusion. From Glacier Point or from Washburn Point, Half Dome can be seen as a thin ridge of rock oriented northeast-southwest, with its southeast side almost as steep as its northwest side except for the very top. Although the trend of this ridge, as well as that of Tenaya Canyon, is probably controlled by master joints, 80 percent of the northwest "half" of the original dome may well still be there.

On March 28, 2009, a large rock slide occured off of Awhiyah Point. The slide happened at 5:26 a.m and damaged a large area under the dome. No one was injured but hundreds of trees were knocked down and a portion of the Mirror Lake trail was buried. The slide registered on seismographs as a 2.5 earthquake.[5]

[edit] In culture

Half Dome in winter

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

Half Dome was originally called "Tis-sa-ack," meaning Cleft Rock in the language 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. Tis-sa-ack is the name of a mother from a native legend. The face seen in Half Dome is supposed to be hers.[6] Tis-sa-ack is the name of a Mono Lake Paiute Indian girl in the Yosemite Native American legend.[citation needed]

Half Dome is included in many company and organization logos, including that of the environmental group, the Sierra Club and the game studios Sierra Entertainment.

Half Dome is the inspiration behind The North Face corporate logo.

[edit] Hiking the Cables Route

Climbers can view the sheer face of Half Dome
Hikers use cables to ascend Half Dome
The cable route gets crowded on the weekends

The Half Dome Cables Route hike runs from the valley floor to the top of the dome in 8.2 mi (13 km) (via the Mist Trail), with 4,800 ft (1,460 m) of elevation gain. The length and difficulty of the trail used to keep it less crowded than other park trails, but on long summer days there can still be a large crowd at the top and on the trail. The hike can be done from the valley floor in a single long day, but many people break it up by camping overnight in Little Yosemite Valley. The trail climbs past Vernal and Nevada Falls, then continues into Little Yosemite Valley, then north to the base of the northeast ridge of Half Dome itself.

The final 400 ft (120 m) ascent is steeply up the rock between two steel cables used as handholds.[7] The cables are fixed with bolts in the rock and raised onto a series of metal poles in late May (the poles do not anchor the cables). The cables are taken down from the poles for the winter in early October, but they are still fixed to the rock surface and can be used. The National Park Service recommends against climbing the route when the cables are down and when the surface of the rock is wet and slippery.[7] The Cable Route is rated class 3, while the same face away from the cables is rated class 5.[8]

The cable route can be crowded. As many as 1,000 hikers per day sometimes climb the dome on a summer weekend.[9] Gloves are recommended for the cable climb, as is proper conditioning, plus sufficient water and food. While Park rules regarding it have see-sawed back and forth, as of 2008 a pile of gloves left by downclimbers for those who did not bring their own can be found at the base of the cables.

The top of Half Dome is a large, flat area where climbers can relax and enjoy their accomplishment. The summit offers views of the surrounding areas, including Little Yosemite Valley and the Valley Floor. A notable location to one side of Half Dome is the "Diving Board," where Ansel Adams took his photograph, "Monolith, The Face of Half Dome (1926)."

From 1971 through August 2007, there have been nine fatal falls from the cables, three in 2007[9]. On June 16, 2007, Hirofumi Nohara, a native of Japan working in Sunnyvale, California, slipped and plunged 300 feet (90 m) to his death.[9][10].

Lightning strikes can be a risk while on or near the summit. On July 27, 1985, five hikers were struck by lightning, resulting in two fatalities[11].

[edit] See also

[edit] References

  1. ^ "MOUNT RITTER - California Mountain Atlas". Peaklist.org. http://www.peaklist.org/CAmtnatlas/tables/whitney/ritter.html. Retrieved on 2008-09-22. 
  2. ^ Jones, Chris (1976). Climbing in North America. Berkeley, California: American Alpine Club / Univ of California Press. pp. 26. ISBN 0-520-02976-3. 
  3. ^ Jones, Chris. Climbing in North America. pp. 27. 
  4. ^ Jones, Chris. Climbing in North America. pp. 207–211. 
  5. ^ Yosemite Rockfall Near Half Dome
  6. ^ Wilson, Herbert Earl (1922). "Legend of Tis-sa-sack". The Lore and Lure of Yosemite. http://www.sacred-texts.com/nam/ca/lly/lly28.htm. 
  7. ^ a b "Half Dome Day Hike". Yosemite National Park. National Park Service. http://www.nps.gov/yose/planyourvisit/halfdome.htm. Retrieved on 2007-08-12. 
  8. ^ Secor, R.J. (1999). The High Sierra: Peaks, Passes, and Trails (2nd edition ed.). The Mountaineers. pp. 391. 
  9. ^ a b c "Death of Sunnyvale hiker on Half Dome called unusual". San Jose Mercury News. 2007-06-19. http://www.mercurynews.com/ci_6180679?source=most_emailed. 
  10. ^ "NPS: Hiker Dies on Half Dome in Yosemite National Park". http://www.nps.gov/yose/parknews/halfdomefall2007.htm. 
  11. ^ "Lightning at Yosemite's Half Dome Kills 2 Climbers; 3 Hurt". Los Angeles Times. Jul 29, 1985. 

[edit] External links

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