366 KEPORT UNITED STATES GEOLOGICAL SURVEY. 



drainage-basiDS, which divide the country, more or less, into different 

 zones, and also to ridges, plateaus, which, notwithstanding the minut- 

 est description, would, without names, be unrecognizable on reference 

 to the map. 



Unga-too-wiss Valley, which opens in a basin called Powell'^i Park, 

 near White Eiver, is only 12 miles west of the TJte agency. It heads 

 from 15 to 16 miles north of Powell's Park near the divide which con- 

 nects the Danforth Hills with Gray Hills. North of that divide lies a 

 basin called Hogback Valley which forms the head of Deep Channel 

 Creek, which, in its general westward course, flows through Coyote 

 Basin before it enters the White Eiver, 20 miles northwest of Powell's 

 Park. 



There is a spring to be found at the head of Unga-too-wiss, and 

 another one in Hogback Valley. Deep Channel Creek keeps and even 

 accumulates a little water in its course to its junction with the White 

 Eiver, while Unga-too-wiss Creek for 12 miles from its source shows 

 no sign of water. The hills that surround these valleys are a true 

 type of the whole country adjacent to the region. Their appearance is 

 desolate and forbidding, while the valleys are still less inviting. The 

 facilities for marching through this country are few on account of 

 obstructions of diversified kinds; the chief ones are the dry- washes, or 

 gullies of a small caHon order, the interminable sage, and the prickly- 

 I)ears; the latter cover the ground for miles. 



Unga-too-wiss and Coyote Basin, are literally cut up by gullies from 

 6 to oO feet, and even as much as GO feet deep ; frequently they are 

 hidden by sage so as to be completely invisible until we reach them. 

 Occasionally we arrive at a spot where a dense growth of large sage, not 

 easy to penetrate, covers the ground. 



YAMPA AND WHITE RIVER DIVIDE. 



The main divide between White and Tampa Elvers is along the crest 

 of the Danforth Hills. It approaches nearest to the White Eiver Valley 

 at Yellow Jacket Pass, where it is but nine miles distant from it. Its 

 winding course, thence along the summit of tbe Danlorth Hills, is north- 

 west until it reaches a point a few miles north of Citadel Plateau, when 

 it is again but nine miles distant from the Yampa Eiver. 



At the head of Coyote Basin a series of sharp cones, the highest of 

 which is not over 7,800 feet above the ocean, aie the last seen on the 

 summit. 



In an almost straight western course, and with only a slight deviation 

 to the south and in still closer proximity to Yampa Eiver, the crest runs 

 for 15 miles, from Wampita Peak to the head of Vale Disappointment, 

 which lies on the Yampa side, while Midland Basin is on the opposite, 

 or White Eiver side. At this point there occurs a sharp turn to the 

 northward which holds for several miles, and thereby brings this divide 

 within six miles of the Yampa Eiver. It afterward continues in a suc- 

 cession of high bluffs in very close proximity to the caiion. These bluffs 

 constitute the northern rim of the Great Yampa Plateau, in whose broad 

 expanse a definite crest is finally lost. 



The only side ridge, showing all the elements and general conditions 

 of an independent hill-cluster and which detaches itself from the main 

 divide and runs toward the White Eiver, is Piiion Eidge, a rugged and 

 singularly eroded upheaval, presenting the usual gentle hill-slope on 

 the east side, while on the opposite or west side the most strangely 

 eroded flanks characterize them. Piiion Eidge forms also a dividing 



