Perhaps the most amazing spectacle of the park is its display of over i oo geysers and 4,000 hot springs. The geysers are con centrated in three adjoining groups upon the middle-west side, but hot springs occur everywhere at widely separated points, one steam jet even issuing from the Grand Canyon depths, more than 1,000 ft. below the rim. The most famous geyser is Old Faithful, which may be taken as typical. The regularity of its eruptions, the violence of its explosions, and the grace and beauty of its water column make it one of the most admired of the park geysers. The interval between eruptions averages 65 minutes, the period of eruption lasts 41 minutes, and it throws into the air a column of water from 95 to 130 ft. in height. The Excelsior geyser, which ceased erupting in 1888, hurled aloft a greater volume of water with appalling fury of action. The Giantess geyser, when in action, is far more powerful than Old Faithful, but plays with less regularity, with intervals of nearly three weeks' duration. Another titanic geyser unexpectedly broke forth in 1928 with furious activity. It hurls water in all directions, some columns to a height of ioo feet. Two major eruptions every 24 hours form its schedule, each eruption lasting for three hours or more, with outbursts at 15 to 20 second intervals.
The Grand Canyon of the Yellowstone is also one of the truly wonderful features of the park. It is a magnificent and pictur esque gorge penetrating deep into the volcanic rocks of the park plateau. It presents on a grand scale a remarkable picture of recent canyon cutting by the Yellowstone river, which, leaving Yellowstone lake at its broad outlet, flows northward through an open valley for about 15 m. and then plunges by two impres sive falls, respectively i io and 312 ft. in height, into the Grand Canyon. The walls of the canyon rise abruptly Boo to i,ioo ft.
above the rushing turbulent stream which cuts the gorge. Much
of the exquisite beauty and impressive grandeur of the region comes from the brilliantly-coloured canyon walls, with their bizarre bands and stripes of soft pink and salmon to blazing Indian red, deep orange in masses, and yellow and green blotches all gayly intermingled. Yellowstone lake is large-2o m. north to south, and 15 m. east to west—irregular in outline, and wooded to the water's edge.
The first recorded visit to Yellowstone Park was made by John Colter in 1810 when he took refuge there from hostile Indians. His story was wholly discredited, as was the story of the next visitor, Joseph Meek, a trapper who visited the region in 1829. The first description of the Firehole geyser basin was written by Warren Angus Ferres, a clerk in the American Fur Company, between 1830 and 1840, but not until 1852 was the region defined and described in its entirety by Father De Smet, the famous Jesuit missionary, who derived his information from the noted Indian scout and frontiersman, Jim Bridger. The first Government expedition sent out in 1859 under the command of Capt. W. F. Reynolds, brought back little authentic information regarding the section, and the reports of private explorers were discredited. Finally the well-equipped expedition under Henry D. Washburn and N. P. Langford, in 187o, established the facts and led to the creation of the Yellowstone National Park.
of Our National Parks, Circular of General Information Regarding Yellowstone National Park, and Rules and Regulations, Yellowstone National Park, all by the National Park Service, U.S. Department of the Interior (published annually) ; A. Hague, Geology of the Yellowstone National Park (1899) ; H. M. Chittenden, Yellowstone National Park (1895) ; R. S. Yard, The Book of the National Parks (1920), and Annual Reports of the super intendent of the park (188o seq.). (W. E. E.)