bunch-grass and a variety of flowering plants; buttercups, daisies, forget-me-nots and other wild flowers, may be found near melting snow-banks in August. In the hot-spring districts are plants with peculiarities both of those common to the desert and those common to the seashore. In the N.E. corner of the park fossil forests rise one above the other. After the destruction of one forest by volcanic eruptions another grew over it; it, too, was buried under volcanic material, and the process was repeated several times.
The native fauna is abundant and varied. The policy of the government which protects game, both in the park and in the surrounding national forests, has induced elk, deer, antelope, mountain-sheep, bears, porcupines, coyotes, squirrels, gophers and woodchucks to take shelter here. There are also a few moose and some beavers. Black, brown and grizzly bears may be seen at almost any time during the summer season feeding on the garbage from the hotels. A few wild bison still remain at large, and besides these there is a herd of about 100 confined within a pasture in the Lamar Valley. The lakes and rivers are well stocked with trout and other fish, and visitors have the privilege of catching a limited number with rod and line. Robins, bluebirds, warblers, chickadees, finches, vireos, wrens, yellow-headed blackbirds, nutcrackers, nuthatches, meadow-larks, sparrows, woodpeckers, swifts, king birds and several other species of small birds are found in the park, but the number of each is not great. Among birds of prey are the golden eagle, bald eagle, hawks and owls. Geese, ducks, cranes, pelicans and gulls are very numerous in the autumn months.
The park is under the supervision of a superintendent who is appointed and instructed by the Secretary of the Interior. It is policed, however, by troops of United States cavalry with headquarters at Fort Yellowstone, near the Mammoth Hot Springs, and the building of roads and other improvements is under the direction of the Secretary of War. The only railway approaches to the park are a branch of the Northern Pacific railway up the valley of the Yellowstone to the main gate at Gardiner, Montana, and a branch of the Oregon Short Line up the valley of the North Fork of the Snake to Yellowstone, Montana. Automobiles are not allowed within the park, and the principal means of conveyance is by stage coaches and by a steamboat on Yellowstone Lake. There are hotels at the Mammoth Hot Springs, at the principal geyser basins and at Yellowstone Lake. The hotels and stage lines open for the tourist season early in June and close in the middle of September.
The strange phenomena of this region were known to some of the Indians; they, were discovered by John Colter, a member of the Lewis and Clark expedition, in 1807; the region was visited by James Bridger before 1840; an account of the geysers was published at Nauvoo, Illinois, in The Wasp, a Mormon paper, in 1842; Captain W. F. Raynolds, of the United States Corps of Topographical Engineers, with full knowledge of Bridger's accounts, was ordered to explore the region in 1859, and yet, chiefly because of the persistent incredulity with which the accounts of the phenomena were received, the region remained practically unknown until 1870. From 1863 to 1866 gold seekers repeatedly confirmed the early reports, and the publication of their accounts in Western papers gradually aroused interest. In 1869 a private exploring party, consisting of David E. Folsom, C. W. Cook and William Peterson, set out from the gold-fields of Montana with the express purpose of verifying or refuting the rumours, and they returned full of enthusiasm. In 1870 a semi-official expedition, led by Henry D. Washburn, the surveyor-general of Montana, and Lieutenant Gustavus C. Doane of the Second United States Cavalry, made the "Yellowstone Wonderland" widely known. A year later an expedition under Dr Ferdinand V. Hayden (1829–1887) made a large collection of specimens and photographs, and with these data, together with the reports of this and the Washburn–Doane expedition. Congress was induced to reserve the area from settlement, which was done by an act approved the 1st of March 1872. In that year further explorations were made, and in subsequent years army expeditions continued the work of exploration. In 1878 a map of the park based upon triangulation was drawn up by the Hayden survey, and in 1883–85 a more detailed map was made by the United States Geological Survey, and a systematic study of its geological phenomena was instituted.
See Arnold Hague, Geology of the Yellowstone National Park (Washington, 1899), "Geological History of the Yellowstone National Park," in the Annual Reports of the Smithsonian Institution (ibid., 1893), and "The Yellowstone National Park," in Scribner's Magazine (May, 1904); W. H. Weed, "Formation of Travertine and Siliceous Sinter by the Vegetation of Hot Springs," in the 9th Annual Report of the Director of the United States Geological Survey (Washington, 1889); descriptions in the 5th, 6th and 12th Reports of the Hayden Geological and Geographical Survey of the Territories (ibid., 1871, 1872 and 1878); J. H. Raftery, Historical and Descriptive Sketch of the Yellowstone National Park, Senate Document No. 752, 2nd Session of the 60th Congress (ibid., 1909); H. M. Chittenden, Yellowstone National Park, Historical and Descriptive (Cincinnati, 1895); and Annual Reports of the Superintendent of the Park (Washington, 1880 sqq.).
YEMEN (Yaman), a province of Arabia, forming the S.W corner of the peninsula, between 12° 35′ and 18° N., and 42° and 47° E., bounded on the N. by Asir and on the E. by the Dahna desert and Hadramut. Ptolemy and the ancient geographers in general include the whole peninsula under the name of Arabia Felix (εὐδαίμων), in which sense they translate the Arabic Yemen, literally “right hand,” for all Arabia S. of the Gulf of Akaba was to the right from their standpoint of Alexandria; the Mahommedan geographers, however, viewing it from Mecca, confine the term to the provinces S. of Hejaz, including Asir, Hadramut, Oman and part of southern Nejd. The Turkish vilayet of Yemen includes Asir, and extends along the Red Sea coast from El Laith in the N. to Shekh Said at the straits of Bab-el-Mandeb; its land boundary on the E. is undefined, except in the S.E., where the boundary between Turkish territory and that of the independent tribes under British protection was defined by an agreement between Great Britain and Turkey in 1904, by a line running approximately N.E. from Shekh Said to the Dahna desert. The main physical characteristics of the province are described in the article Arabia. A lowland strip 20 to 30 m. wide extends along its western and southern coasts, skirting the great mountain range which runs along the whole western side of the Arabian peninsula, and attains its greatest height in the Jibal, or highlands of Yemen; beyond this mountain zone the interior plateau falls gradually towards the N.E. to the Dahna desert.
The lowland, or Tehama, is hot and generally sterile; it contains oases, however, near the foot of the mountains, fertilized and irrigated by hill streams and supporting many large villages and towns. The most important of these are Abu Arish, Bet el Fakih and Zubed in the western Tehama, the latter a thriving town of 20,000 inhabitants and the residence of a Turkish kaimakam; and Abyan and Lahej, the chief place of the independent Abdali tribe, in the southern Tehama. Hodeda and Aden are the only ports of commercial importance, Lohaia and Ghalefika have sunk to insignificant fishing villages, and Mokha, the old centre of the coffee trade, is now almost deserted. The Jibal forms a mountainous zone some 50 m. in width rising steeply from the foothills of the Tehama to an average height of 9000 ft.; many summits exceed 10,000 ft.—the highest fixed by actual survey is Jebel Manar, 10,565 ft., about 10 m. E. of the town of Ibb. With its temperate climate and regular rainfall, due to the influence of the S.W. monsoon, the Jibal must be considered the most favoured district of Arabia. The villages are substantially built of stone, often picturesquely situated on the spurs and crests of the hills, the houses clustering round the dars or towers which dominate the cultivated slopes and valleys. The principal crops are wheat, barley, millet and coffee, the last-named more particularly on the western slopes of the range within reach of the moist sea-breezes. In many places the hillsides, otherwise too steep for cultivation, are cut into terraced fields supported by stone walls; the name given by the Greek geographers to the range of S. Arabia was no doubt intended to describe the step-like appearance of the hills due to this method of cultivation. A special characteristic of the Yemen highlands is that fields and inhabited sites are found at the highest elevations, the mountain-tops forming extensive plateaux, often scarped on every side and only accessible by difficult paths cut in the cliffs which encircle them like the escarpments of a natural fortress; a remarkable example of this is Jebel Jihaf on the Aden border, 8000 ft.
