478 EEPORT UNITED STATES GEOLOGICAL SURVEY. 



the total fall is 1,304 feet iu a distance of 24 miles, being an average of 

 54.3 feet per mile. As far as the extremity of the Washburn Mountains, 

 a distance of 12 miles, the caiion continues to increase in depth, both 

 by the fall of the stream and the rise of the plateau, and the extreme 

 depth, 1,200 feet, is attained at this point. Thence the depth decreases 

 rapidly, and at the mouth of Tower Creek it is but five or six hundred 

 feet deep on the west side, and about 1,000 feet on the east side. The 

 width of the caiion at the top ranges from one-fourth of a mile to one 

 mile, and the angle of slope of the walls from the top to the water's edge 

 ranges from 45° to 75°, with a horizontal line. 



The Yellowstone receives several tributaries from each side in its 

 progress down the caiion. From the east, Jasper, Agate, Broad, and 

 Orange Creeks come in, and from the west a number of small streams, 

 heading in the "Washburn Mountains. As is usually the case in a land 

 of canons, these branches have much less erosive power than the main 

 stream, and consequently reach it at a much higher level, necessitating 

 a very rapid slope at the end or an abrupt fall. Many of these streams 

 make very fine falls in reaching the canon walls. This is particularly 

 the case with the little streams on the west. They flow on the surface 

 of the plateau, with a very gentle current, and have to make the whole 

 descent to the bed of the caiion in a small fraction of a mile. The 

 streams from the east, which head high up in the Amethyst Eidge, have 

 long courses and drain considerable areas. These streams cut canons 

 of considerable depth before they reach the main stream. 



a HE WASHBURN MOUNTAINS. 



This group stands near the middle of the Park in longitude, and in 

 latitude about one-quarter the length of the Park from its northern 

 boundary. It is in the form of a semicircle, the middle of the convexity 

 being towards the southwest and opening towards the Yellowstone. 

 Its diameter is about 8 miles. The whole of this great amphitheater is 

 drained by Tower Creek and its branches. The group contains alto- 

 gether about twenty-five summits, ranging in height from 9,000 to 

 10,400 feet. The highest peak of the group is Mount Washburn, 10,346 

 feet above sea-level. This peak is very easy of access, and as the trail 

 up the river i>asses very near the summit it is a very much-visited 

 mountain. Card- receivers, consisting of old peach and sardine cans, are 

 cramined with the names of visitors, from Cabinet officers down to the 

 Toms, Dicks, and Harrys of the great unwashed. The earliest date is 

 that of Lieutenant Doane's (the Washburn) party, 1870. 



Southwest of Mount Washburn, and distant from it but 2 miles, is a 

 sharp cone rising to a height of 9,988 feet. This I have named Dun- 

 raven Peak, in honor of the Earl of Dunraven, whose travels and 

 writings have done so much towards making this region known to our 

 cousins across the water. This is the peak which rises directly up from 

 the west side of the pass in the Washburn Mountains, on the trail to 

 the Falls. 



The southern slopes of the convexity of the Washburn Mountains are 

 drained by small streams flowing into the Yellowstone, the largest of 

 which is Cascade Creek. This stream collects its waters during a very 

 leisurely course through a series of marshy meadows, and enters a canon 

 only a mile above its mouth. The western slopes of these mountains 

 are tributary to the East Fork of Gardiner's Eiver, while most of the 

 northern slopes drain into the Yellowstone through Blacktail, Geode, 



