54 REPORT OF THE SECRETARY. 



The northern area is occupied by the valley of Grand Eiver and the 

 foot-hills of the Eoan Plateau, forming the Book Cliffs. The valley of 

 the Grand extends down the north side of the river for upward of a 

 hundred miles, with an average width of 10 miles, aud is at present 

 about as valueless a piece of country as there is in any part of the 

 West.- There is no good water except in the Grand, which is in low canon 

 most of its course and consequently difficult of access. The soil is a 

 bluish-gray alkaline clay, derived from the weathering of Cretaceous 

 shales, which, when dry are deep and powdery, and when wet become 

 a mud of almost incalculable depth. There is but little vegetation of 

 any kind. Part of the valley might be irrigated from the river aud 

 thus become of value. The geology is comparatively simple, the differ- 

 ent formations dipping away from Grand Eiver in regular order from 

 Triassic to Green Eiver Tertiary, the latter forming the summit of the 

 cliffs. Coal occurs along the cliffs, but at no locality visited was it of 

 economical importance. The most interesting discovery was that of 

 asphaltum springs, on the southern side of the crest of the Eoan Pla- 

 teau. The mineral tar flows from fissures in Tertiary sandstones and 

 hardens as it pours down the walls of the canons on which it occurs. 

 About a dozen of these springs were noted^ some of them in connec- 

 tion with sulphur springs. 



The party, after finishing the northern area, started for Eawlins, on the 

 Union Pacific Eailroad, which they reached October 23, having been in 

 the field two months. In that time they traveled about 1,100 miles, 

 locating 55 topographical stations, and surveying 4,000 square miles in 

 about 35 working days, the rest of the time being occupied in marching 

 to and from and between the districts. 



The White Eiver division was directed by George B. Chittenden, as 

 topographer, accompanied by Dr. F. M. Endlich, as geologist. The dis- 

 trict assigned to this party began on the east at longitude 107° 30', 

 joining the work previously done, (1874,) and extended westward to lon- 

 gitude 109° 30', or about 27 miles over the Colorado line into Utah. Its 

 southern boundary was north latitude 39° 38' or the approximate line 

 of the Book Cliffs, while the White Eiver formed the northern limit. 

 The area surveyed comprised about 3,800 square miles. In working up 

 the topography of this district the party spent 48 days of absolute field- 

 work, made 41 main topographical stations and 16 auxiliary ones, and 

 traveled within the district about 1,000 miles. The country has hith- 

 erto been almost entirely unexplored, and had been described by the 

 nearest settlers as a broken canon country, extremely dry. It was 

 marked on the maps as a high, undulating plateau, with fresh-water 

 lakes and timber. The party saw no lakes of over 400 yards diameter, 

 and but two or three of these, and timber was rather the exception. 

 The country is nearly all inhabitable, both winter and summer, and 

 considerable portions of it are valuable. About three-quarters of it is 

 within the limits of the Ute Indian reservation. 



