The United States has the most climbers among foreigners, followed by Germany and the United Kingdom. More than 140 climbers have perished on Aconcagua, mostly from altitude sickness problems, but also from falls, heart attacks, hypothermia, and other weather-related causes. The actual death toll may be higher, since some bodies are never found. Aconcagua is the highest mountain in both Argentina and Chile. At 2976 meters (9843 feet), it is not only the highest peak in South America, but also in the Southern Hemisphere as well as in the Western Hemisphere. The previous record holder, Mount Everest in Nepal, is only slightly higher at 2968 meters (9744 feet). Aconcagua is used for climbing because of its large number of peaks of over 4000 feet, which are generally more difficult to reach than those below this height. It is a popular destination with experienced climbers from all over the world who take part in events called "rope-ups". These are when groups of climbers use their own ropes to climb together up very steep sections of the mountain. The first American to ascend Aconcagua was Edwin Dwight Davis, who reached the top on April 23, 1909. The best known route up the mountain is the traditional one through Chilean territory, which requires six to eight days to complete.