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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,

Washington, D. C., December 1, 1878. SIR: I have the honor to present for your consideration a brief sunmary 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, consisting 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 localities. 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 ineridian there is no area so densely timbered with the exception of Washington Territory. The mean elevation of the park above sea-level is be. tween 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 improve. inents. 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 Yel. lowstone 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 smalt 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 have their chief representative in Yellowstone Lake. Detailed investigations were made at many points of interest, and a fine mineralogical collection was made.

In the mean time Mr. Holmes sketched every square mile of the park, an area of 3,500 square miles. In such minute detail was the work done that the economic resources, as well as all the minor features of the geol. ogy, can be laid down on a map on a scale of one mile to an inch with the greatest care and minuteness. The great variety of forms which the mountains in and around the park assume can be presented to the eye by panoramic views with wonderful distinctness.

The third division, under Mr. F. A. Clark, surveyed the Wind River Mountains, a portion of the Wyoming Range, the Gros Ventres Range, with a large area in the Snake River Valley. Mr. Clark made 31 gradienter stations and 15 compass stations. The area lies between latitude 430 and 44o and longitude 1090 15' and 1110. This includes the upper portion of the Wind River Mountains, with portions of the Wyoming ming Range, the Gros Ventres Range, and portions of the Shoshone Mountains and the Owl Creek Range; also the sources of Green River, Hoback Basin, and upper waters of Wind River. Mr. St. John acted as geologist and Mr. N. W. Perry as mineralogist to this party. Their reports will prove of general interest. Mines of gold, silver, iron, and vast beds of gypsum, as well as many other minerals, were found.

In the prosecution of the field-work of the survey during the past season a photographic division was again put in operation, after an interval of two years, under the leadership of Mr. W. H. Jackson, who has been connected with the survey as its photographer during the past nine years.

Leaving Point of Rocks, on the Union Pacific Railroad, on July 24, the first points of interest were reached on the western flank of the Wind River Mountains. Two side trips, undertaken in connection with Mr. Wilson, in charge of the primary triangulation, were made to the crest of the range, and some grand views of that remarkable region were obtained. From the summit of Frémont's Peak views were made of an immense glacier now occupying its eastern slope. Fine views were also obtained of the great glaciated plateau lying between the plains and the crest of the range.

Proceeding next to the vicinity of the Grand Tétons, lying to the east of the head waters of the Snake River, several magnificent views of the remarkable range in which they occur were made from the neighborhood of Jackson's Lake.

Reaching Shoshone Lake the 18th of August, the entire month following was devoted exclusively to the careful photography of all the remarkable phenomena connected with the hot springs and geysers of the various basins within the Park. Especial attention was paid to the almost unknown but exceedingly interesting features of the new Shoshone and Red Mountain Basins. The “ Fire Hole” and “Mammoth Hot Spring" Basins were again gone over, and the experience derived from the work clone here in former years shows its benefits in the remarkably effective views obtained this season. At this latter basin many detailed as well as general views were made with especial reference to the future production of an exact model in plaster of the whole group.

On the homeward route, which was by the way of the Upper Yellowstone, across the headwaters of the Snake to the Wind River and thence via Camp Brown to the railroad, a number of very effective views were made, particularly about the Grand Falls and the cañon of the Yellow. stone. At the Yellowstone Lake some very fine views were made, but that region was left somewhat incomplete in consequence of a prolonged snow-storm.

As the Togwotee Pass some characteristic views were obtained of the remarkable breccia mountains, whose castellated forms adorn that portion of the continental divide, and also some of the curious “bad lands" farther down on Wind River.' The season's work closed at Camp Brown, where some excellent portraits and groups were made of the Bannock prisoners in confinement at that post.

A brief summing up of the season's operations of three months, much of which time was characterized by extremely inclement weather, shows an increase to the already very extensive collection of the survey, of 45 negatives 11 by 14 inches in size, and 110 of smaller ones, 5 by 8. The number was purposely kept small that a better quality might prevail in them.

The geologist in charge accompanied the photographic division, and the route pursued gave him an opportunity to secure a very accurate general knowledge of the geological structure of a large area. The Wind River Range proved one of remarkable interest. It has a trend about northwest and southeast, with a length of about 100 miles. On the west side all the sedimentary belts have been swept away, down to the Archæan, older than the Wahsatch, and the latter formation rests on the Archæan rocks all along the base of the range, seldom inclining more than 50 to 100. On the east side of the range the seams of sedimentary formations usually known to occur in the northwest are exposed from the Potsdam sandstone, which rests upon the Archæan rocks, to the Cretaceous inclusive.

Along the northwestern portion of the range the Wahsatch Group only is seen for some distance, but as we proceed down the Wind River Valley the formations appear one after the other, until at the lower end the entire series is exposed. The Wind River Range may be regarded as originally a vast anticlinal, of which one side has been entirely denuded of the sedimentary, except the Middle Tertiary. On the same side of the range the morainal deposits and glaciated rocks are shown on a scale such as we have not known in any other portion of the West. Three genuine glaciers were discovered on the east base of Wind River and Frémont Peaks, the first known to exist east of the Pacific coast.

The morainal deposits are also found on a grand scale in the Snake River Valley, on the east side of the Teton Range. The numerous lakes have been the beds of glaciers, and the shores of the lakes are walled with morainal ridges. North of the Teton Mountains the prevailing rocks are of modern volcanic origin, and in the Yellowstone Park the hot springs and geysers are the later manifestations of the intense volcanic activity that once existed. All these interesting features were studied with care, and the results will be elaborated for the twelfth annual report of the survey.

It was with great pleasure that the geologist in charge reviewed the ground passed over in 1860, over eighteen years previously. In the years 1859 and 1860 he acted as geologist to the exploring expedition under the command of Col. William F. Raynolds, now of the Engineer Corps, U. S. A. A portion of the geological report made on that expedition will be reprinted in the 11th annual report.* A geological map accoinpanies this report, which embraces Dakota and Montana, with portions of Idaho, Wyoming, and Colorado.

* Geological Report of the Exploration of the Yellowstone and Missouri Rivers, nder the direction of Capt. (now Lieut. Col. and Brevet Brig. Gen.) W. F. Raynolds, prps of Engineers, 1859-1860. By F. V. Hayden,

The publications of the survey during the past year have been numerous and important. The atlas of Colorado, in twenty sheets, has received the most unqualified praise for its accuracy and beauty, both in this country and in Europe. The following analysis of the atlas was written for the London periodical “Nature," of September 12, by Prof. Archibald Geikie, director of the geological survey of Scotland and professor of geology in the University of Edinburgh, and one of the ablest geologists in Europe :

In the magnificent atlas just issued by the Department of the Interior we have the consummation and crown of all the labors which Dr. Hayden and his staff have carried on so triumphantly for the last five years, and of which they have already given us so much interesting and important information in a series of annual reports. Before examining the work from a scientific point of view, no reader can refrain from expressing his admiration of the style in which the atlas has been produced by the United States Government. As a specimen of cartography, typography, and lithography it is altogether worthy of the highest praise. For beauty and, indeed, sumptuousness of execution, it may be classed with those livres de luxe which from time to time have been issued from the National Imprimerie of France.

The atlas consists of two series of maps, the one of a general, the other of a detailed kind. The first series, on the scale of twelve miles to one inch, comprises four sheets, each embracing the whole State of Colorado and part of the neighboring territory. The first of these illustrates the system of triangulation adopted in the survey; the second shows the drainage system of the area; the third, by a simple and clear arrangement of colors, exhibits at a glance the economic features of the whole region-the agricultural land, pasturage, forests and woodlands, sage and bad lands, mineral tracts, and the portions rising above the limit of timber-growth; the fourth contains a con• densed and generalized geological map of the same territory. Nothing can surpass the lucidity of expression and artistic finish of these maps.

The second series-twelve in number-is on the scale of four miles to one inch, and consists of six topographical sheets and six identical sheets, colored geologically. The topographical details, though numerous, are so selected as not to neutralize each other or mar the broad, clear picture which the maps were designed to be. By means of contour-lines of 200 feet vertical distance, the surface-configuration of the whole region is depicted as in a model. We can follow the lines of the broad valleys, of the deep, narrow cañons, and of the hundreds of minor tributaries which have scarped out their courses on either side. Here we look down upon a vast table-land, deeply trenched by stream-channels; there upon a succession of bold escarpients or mesas, which bound the table-land and hem in the neighboring valley. Huge mountain-ranges rising out of the plateaus are so vividly drawn that they seem to stand out of the paper; yet no shading is employed. All the effects of inequality are produced by contour lines, so faithfully set down that a single line may be tracked in its sinuous course along thó whole of a mountain front until it comes out upon the table-land beyond. When will our map-makers learn to use this, the only true method for expressing the surface of a country? The best of our atlases are distigured by strips of shading running across the map, like so many caterpillars, to represent mountain ranges. Even our ordnance maps, so admirable in most respects, are sometimes so loaded with shading that a steep hillside, only a few hundred feet high, is made as black as our highest mountains, and the topographical names can hardly be read, even with a magnifying-glass.

But, above all, welcome are these six geological maps. In the previously published maps and charts accompanying the annual reports only small detached areas were represented, and even from the careful descriptions of the various geologists of the staff, it was hardly possible to frame a satisfactory conception of the geology of Colorado as a whole. Ever since the marvels of its deep gorges and vividly painted cliffs were made known, that region has possessed a high interest to the geologist. He has now the means of gratifying his desire for further knowledge. With the help of these maps and the two accompanying sheets of sections, he can realize most satisfactorily every great feature of Colorado geology. The ancient Archæan ridge—the nucleus or backbone of the American Continent-may be traced running north and south nearly along the present hydrographical axis of the country. Flanking that ridge comes a series of Palæzoic deposits, the oldest of which have been identified palaeontologically with Silurian formations. Rocks regarded as of Devonian age overlap the Silurian beds, and repose against the ancient crystalline ridge on the southwest side of the San Juan Mountains. They are soon buried under later accumulations, and they seem to be of but local development, since in most places where the rocks are found in juxtaposition, the Silurian are directly succeeded by Carboniferous strata. These last-named rocks cover large tracts of country, running as bands round the Archæan area, and lying in basins across it. Far to the west, where the Grand River has so deeply trenched the Utah plateau, the flat Carboniferous beds appear from under the

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