I 



jiARviNE.] GEOLOGY TOPOGRAPHICAL FEATURES. 91 



two short rifts, or breaks in upturned strata, to the Hot Springs, wliicli 

 by their reputation and position virtually form the center of the Park. 

 Here the stream enters a shallow canon three or four miles long, after 

 which, for over fifteen miles, its course is through an extensive basin, 

 much of the region along its lower course being river-bottom land. 

 Williams Eiver joins it from the south, while Corral and Troublesome 

 Creeks flow into it from the north. ^ The Muddy from the north and the 

 Blue from the south, however, are the two principal tributaries of the 

 Grand and join it at nearly the same point, just before it enters the 

 caiion through the Park range which carries it from the Park. This 

 lowest point in the Park is about 7,180 feet above tide-water, while the 

 Hot Springs are 7,700 feet, and Grand Lake approximately 8,150 feet 

 above the same. 



The Williams Elver takes its rise in the deep western canons of the 

 Clear Creek loop and the Mount Byers ridge. Issuing from this granite 

 country it flows for several miles through a wide flat basiu tributary to 

 that of the Lower Grand. 



The Mount Byers ridge extends from the base of that mountain as a 

 quite straight and even-topped divide, separating the Frazier and Will- 

 iams waters, and falls abruptly to the Grand at the Hot Springs. On 

 the west side of the Williams Valley is the long, gentle, eastern slope of 

 the symmetrical Williams River Mountains, which reach an altitude of 

 about 11,400 feet, or nearly to the timber-line. 



On the north side of the Grand the Willow, Corral, and Troublesome 

 Creeks drain an area which, being a geological unit, has uniform topo- 

 graphical features. The culminating point of this mass is Park View 

 Peak, near the northern line, 12,430 feet high, and directly overlooking 

 the ISTorth Park. On either side of Park View Peak the divide between 

 the two parks falls, the descent on the east to the headwaters of the 

 Willow being about 2,620 feet to an excellent pass connecting the 

 parks; a serrated region of not much greater height follows, and 

 finally the abrupt rise to the Medicine-Bow Eidge. South of this line 

 and parallel with the southern end of the latter ridge is a high, even- 

 topped ridge, reaching to timber-line, which is quite surrounded by the 

 eastern branches of Willow Creek. West of Park View, between the 

 two Troublesome Creeks, the ridge is also depressed as on the east, but 

 at the west fork it rises in a high lava-capped plateau, falling on the 

 west to the Upper Muddy. The next point of elevatioh of this mass is 

 Corral Peak and White-Face Mountain, lying south of Park View, be- 

 tween the Troublesome and Willow Creeks and north of the Hot 

 Springs. These also are due to lava caps protecting the softer horizon- 

 tal sedimentary rocks below. Between all these points and extending 

 south to the Hot Springs and across the Grand, somewhat, is a 

 broken countr^^ chiefly made up of very numerous small spurs abutting 

 against the streams, in all of which the tendency is to a more 

 or less definite terrace form, the broken terraces rising in steps to the 

 higher lands beyond. The two forks of the Troublesome leave this region, 

 where they join, and for the rest of the course the stream is in a flat 

 basin country like that of the Lower Williams Eiver, tributary to the 

 Grand. This lower basin is separated by a low hillj^ divide from the 

 Lower Muddy. 



The drainages of the Muddy and Blue alone remain to be referred to. 

 Both lay at the eastern base of the Park range, and form very well de- 

 fined valleys, trending in nearly the same general direction, and facing 

 one another. The valley of the Upper Muddy is broad and shallow, 

 presenting a strong contrast to most valleys of this country. Its gen- 



