Yellowstone National Park, Wyoming

Information: The National Park is open throughout the year, but many roads are closed from November to April. Most visitors come in summer when, as a result, the Grand Loop can reach saturation point and most overnight accommodation is booked. But autumn (until mid Oct.) and late spring, when a lot of young animals are being born, are also good times to visit.There are five Visitor Centers in the Park and a good supply of overnight accommodation in hotels and camping sites (though in summer advance booking is advisable). Budget accommodation is available in places near the Park entrances, e.g. Gardiner or Cooke City, both in Montana.Origins There were violent volcanic eruptions in the area now occupied by the Yellowstone National Park some 2 million years ago, again 1.2 million years ago and finally 600,000 years ago. After the last eruption and the collapse of the crater a huge caldera was formed. The magma chamber (the "hot spot") that brought about these eruptions still generates a great deal of heat, as is shown by innumerable post-volcanic, which, amid constant seething and hissing, shroud the landscape in a thick veil of steam. The continuing instability of the ground is shown by the frequency of earth tremors in the area.The forests of Yellowstone had long been familiar territory to the Indians when John Colter led a first expedition here in 1807. The American government recognised the unique nature of the area very early on and in 1872 it was declared a National Park, the first in the United States.The National Park has a varied range of flora, from desertic vegetation at the north entrance to sub-alpine meadows and forests.There are from time to time devastating forest fires in the National Park, most recently in the summer of 1988, when large areas of forest in the north-western part of the park were destroyed.Fauna In this relatively intact natural region there is an abundance of wild life. In addition to bison, various species of deer (red deer, wapiti, mule deer), bighorn sheep, beavers and marmots, there are also elk, pronghorn antelopes, black bears, grizzlies and coyotes. In the air swoop ospreys and on water there are pelicans, various species of ducks and geese, and trumpeter swans. The reintroduction of wolves in recent years has had a mixed reception.