Jemez Mountains
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The Jemez Mountains ('heɪmez) are a group of volcanic mountains in New Mexico, United States. Highest point in the range is Chicoma Mountain (also spelled Tschicoma, Tchicoma) at an elevation of 11,561 feet (3524 meters). The town of Los Alamos and Los Alamos National Laboratory adjoin the eastern side of the range, while the town of Jemez Springs is to the west. Pajarito Mountain Ski Area is the only ski area in the Jemez.
The Jemez Mountains are a classic example of intracontinental volcanism and consist of a broadly circular ridge surrounding the famous Valles Caldera, actually a collection of at least two and possibly more distinct caldera features. The most recent known eruption was a basalt flow dated to 50,000 to 60,000 years before the present; however, most of the volume of the range is composed of rhyolite. The two most recent caldera-forming eruptions, dated to about 1.4 million and 1.1 million years ago, produced massive ignimbrite deposits known as the Otowi and Tshirege members, respectively, of the Bandelier Tuff. Much of the material in these deposits now forms the Pajarito Plateau, a scenic region of canyons and mesas on which Los Alamos is situated. Redondo Peak, the second highest summit in the range at 11,254 ft (3431 m), is a resurgent dome in the middle of the Valles Caldera, which also contains several smaller domes separating the caldera into several valley-like features.
Much of the range is on federal land, including Santa Fe National Forest, Bandelier National Monument, and the Valles Caldera National Preserve. Hiking trails crisscross the range and lead to many of the summits, although some regions are closed to hikers either because of environmental restrictions or because they are on the territory of Santa Clara Pueblo or private land holders. The summits are generally easy to climb (in good weather) and require no technical-climbing skills, but rock climbing is done on some of the basalt cliffs near Los Alamos and elsewhere in the range. The mountains also are home to Pajarito Mountain, a small downhill ski area and offer some opportunities for cross country skiing, although not every winter produces enough snow to support this recreational activity. The region is prone to forest fires because of the tendency for springtime to be hot, dry and windy, creating conditions under which fires caused by human activities or lightning can spread rapidly. The Cerro Grande Fire in the year 2000 burned over 40,000 acres (160 km²) of forest and destroyed a number of homes in Los Alamos. Parts of Los Alamos National Laboratory were also damaged, although none of the laboratory's special nuclear materials (plutonium, uranium, etc.) were threatened or released.
