4 EEPOET UNITED STATES GEOLOGICAL SURVEY. 



days a place of rest for Mr. Evarts, who was lost for a number of weets 

 in the Park in 1870. 



On the 24th I reascended Mount Sheridan for the purpose of finishing 

 my observations and sketches. On the following evening we joined the 

 main party at Shoshone Lake. 



It became necessary, on account of want of supplies, to hasten to 

 Gardiner River Springs. We crossed first to Bechler's Fork and theuce 

 to the Madison Eiver. Descending this, we visited the Geyser Basins, 

 and worked as far to the west as the plateau west of Gibbon's Fork. 

 Ascending the East Fork of the Madison, we reached the Yellowstone 

 River at Crater Hills and carried our iuvestigations down the left bank 

 of the river to the Falls, thence down the canon, across Mount Wash- 

 burne, and, by way of Baronett's Bridge, to Mammoth Springs. 



While camp remained at the springs we visited Sepulchre Mountain, 

 Electric Peak, and Mount Evarts, and on the 12th of September set out 

 for the East Fork and Yellowstone Lake. Offr work went on with good 

 success until the 23d of September, when a series of snow storms set 

 in. Our work was much retarded, and finally, on the 13th of October, 

 we were compelled to forego further work in the Park and make all 

 haste for Bozeman, Montana, which place we reached on the 18th. 



GENEEAL SUEEACE FEATURES. 



The surface features of the Park present a great diversity of charac- 

 ter. A general impression x>revails amongst people who have derived 

 their knowledge from books and newspaper reports, that the Park 

 abounds in grand scenery. On the contrary, the greater part consists of 

 undulating and broken table-lands, densely timbered and extremely 

 monotonous. There are, however, along the north and east, bordering 

 ranges of lofty and picturesque mountains, and the canons which cut their 

 way through the table-lands and along the bases of the ranges possess 

 a very deeii interest. 



A large part of the Park, especially that bordering the Yellowstone 

 Eiver and its chief tributaries, is of the attractive parked country so 

 characteristic of the less rugged upland valleys of the Rocky Mountains. 



The drainage of the Park area is divided between three distinct sys- 

 tems — the Yellowstone River, which has about three-fifths, and the 

 Madison and Snake Rivers, which have about one-fifth each. The Yel- 

 lowstone River runs in a sinuous course from the southeast to the north- 

 west corner of the Park, and in the upper half of its course is in open 

 valleys. In the northern half, that is 1o say, from the Falls to the 

 mouth of Gardiner River, it is almost continually in cafions. The 

 course of the river serves to separate, approximately, the mountain dis- 

 tricts from the undulating and flat districts. With the exception of a belt 

 that extends from the Lake down the east side of the canon to the East 

 Fork, the country east of the river is mountainous. The belt of flat land 

 just mentioned belongs properly to the great undulating i)lateau that 

 stretches out to the south and west, and which has its monotony broken 

 by the caiaons, of the various rivers and by occasional groups of mount- 

 ains. 



Across this monotonous district, which I shall call the Park Pla- 

 teau, the ocean divide passes. Within the Park district this divide is 

 not marked by any elevation or ridge that lifts itself above the general 

 level. To the west, 30 miles beyond the limits of the Park, the divide 

 sweeps across the extreme southeastern group of the Madison Mount- 

 ains, and on the southeast finds its first marked elevation in the vol- 



