PRELIMINARY REPORT OF THE FIELD WORK OF THE UNITED STATES GEOLOGICAL AND GEOGRAPHICAL SURVEY OF THE TERRITORIES FOR THE SEASON OF 1878. By F. V. HAYDEN. OFFICE GEOLOGICAL AND GEOGRAPHICAL SURVEY OF THE TERRITORIES, SIR: I have the honor to present for your consideration a brief summary of the field work of the United States Geological and Geographical Survey under my charge, for the season of 1878. Owing to the length of the session, Congress did not pass the usual appropriation for the work of the survey until July, and consequently the field labor was of comparatively short duration. The headquarters of the survey was at Cheyenne, Wyo., the same as the preceding season. Four parties were organized, but in such a manner that in case of necessity they could be divided for special duty. All our outfit and animals were transported from Cheyenne to Point of Rocks and Green River Stations, on the Union Pacific Railroad, and from thence the parties pursued their way northward to their respective fields of labor. To the first division, in charge of A. D. Wilson, was confided the primary triangulation of the entire area to be surveyed. Eight of the most important peaks were employed as stations, with some minor points. Among the more important stations were Wind River, Fremont's, Grand Teton, and Sawtelle's Peaks (near Henry's Lake); also several of the most conspicuous points in the Yellowstone Park. This division was robbed, near Sawtelle's Peak, of all its animals and a portion of its outfit, so that at least half of the most valuable time for work during the season, was lost. Had it not been for this misfortune at least double the work would have been accomplished. The Yellowstone Park at this time forms the most extensive unoccupied area in the West, and, surrounded by great ranges of mountains, becomes a resort for hostile bands of Indians when pursued by the troops. To the division of the survey in charge of Mr. Henry Gannett was intrusted the work of making a specially-detailed geological and geographical survey of the Yellowstone National Park. The party was divided into two sections for the prosecution of this work; one section, consisting essentially of Mr. Gannett, topographer, and Mr. W. H. Holmes, geologist, made the general survey of the park, while the other, consist ing of Dr. A. C. Peale and Mr. J. E. Mushbach, were occupied in making detailed studies and maps of the geyser and hot-spring localities, a work of the greatest interest and value to the scientific world. Material was secured for a detailed map, on a scale of one mile to an inch, of the Yellowstone Park, an area of 3,500 square miles; and for maps on a large scale of all the principal geyser and hot-spring locali ties. In the survey of the park, forty-seven important stations were occupied for secondary triangulation and topography, besides a large number of lesser importance. On all the principal stations, stone monuments were erected for future reference. Several groups of geysers and hot springs, not heretofore known, were discovered. The area of the Yellowstone Park is, in round numbers, 3,500 square miles. Its surface is in large part level or rolling, with several groups and short ranges of mountains diversifying it. In the eastern part, extending its whole length and forming the water-shed between the Yellowstone and the Bighorn, stand the rugged volcanic peaks of the Yellowstone Range. Nearly all of the park is covered with a dense growth of magnificent pine timber; indeed, west of the one hundredth meridian there is no area so densely timbered with the exception of Washington Territory. The mean elevation of the park above sea-level is between 7,000 and 8,000 feet, which implies too cold a climate to admit of agriculture, except in certain very limited localities. It is safe to say that not more than one per cent. of this area can, by any possibility, be used for agricultural purposes. Except along the northern border, grazing land exists only in small patches of a few acres each. There are not, so far as is known, any mines or mineral deposits within the park. The only occupied buildings within the park are at the White Mountain Hot Springs, where Mr. J. C. McCartney has made some improvements. A good wagon-road extends from Bozeman, Mont., to this point. From these springs, which form the usual point of departure for excursionists, there are excellent trails to all points of interest within this region; to Amethyst Mountain, Yellowstone Falls and Lake, the Mud Geysers, and other objects of interest on Yellowstone River and the Geyser Basins. It is unnecessary to specify these trails, as they traverse the country in all directions. In his campaign against the Nez Percés, in 1877, General Howard constructed an excellent wagon-road up the Madison to the Lower Geyser Basin, and thence across to the Yellowstone. His road up the Yellowstone is impassable at present for wagons. Mr. W. H. Holmes acted as geologist to the second division. The first month of the season he was with the fourth division, which proceeded from Point of Rocks Station northward, along the west side of the Wind River Mountains, and up the Snake River Valley to the Yellowstone Park, where he joined the second division. In the mean time he was engaged in making sketches, panoramic views, and geological sections of the intermediate country, all of which will prove of the highest importance in illustrating the geological structure of this most interesting and complicated region. The latter part of the summer was spent in making detailed geological examinations in the district that includes the National Park. The greater portion of the park was found to be covered with somewhat uniform flows of the ordinary volcanic rocks. Features of more than ordinary geologic interest occur, however, along the northern border of the park district. Here a small belt, not more than 15 by 30 miles in extent, contains a fair epitome of the geology of the Rocky Mountain region. The whole series of formations from the earliest to the most recent are almost typically developed. The only marked irregularity in the succession of geologic events occurred during the great mountain-building period of the Middle Tertiary. After that followed a number of inferior oscillations of the surface, during which an extensive series of recent Tertiary and volcanic rocks were deposited. Connecting this period with the present are the deposits of a number of great lakes, which at the present time |