246 ANNUAL EECORD OF SCIENCE AND INDUSTRY. 



ers in Colorado and Eastern Utah is hardly above latitude 

 37 45'. 



The Grand River Division was directed by Mr. Henry Gan- 

 nett, topographer, with Dr. A. C. Peale as geologist. Mr. 

 James Stevenson, executive officer of the Survey, accom- 

 panied this division for the purpose of assisting in the man- 

 agement of the Indians, who last year prevented the com- 

 pletion of the work in this locality by their hostility. 



The greater portion of the work of this division lay north 

 of the Grand River, limited on the north by the parallel of 

 39 30', and included between the meridians of 108 and 

 109 30'. 



This division took the field at Canon City, Colorado, about 

 the middle of August. The party traveled nearly west, up 

 the Arkansas River, over Marshall's Pass, and down the To- 

 michi and Gunnison Rivers to theUncompahgre (Ute) Indian 

 Agency. Here they secured the services of several Indians 

 as escort in the somewhat dangerous country which they 

 were first to survey. This area lying south of the Sierra La 

 Sal was worked without difficulty. It is a broken plateau 

 country, and presents many curious pieces of topography. 

 Eleven days were occupied in this work. 



The Grand River, from the mouth of the Gunnison to that 

 of the Dolores, i. e., for nearly a hundred miles, flows along 

 the southern edge of a broad valley, much of the way being 

 in a low canon, one hundred to two hundred feet deep. The 

 course of the river is first northwest for twenty-five miles, 

 then, turning abruptly, it flows southwest, and then south for 

 about seventy-five miles. This valley has an average width 

 of twelve miles. It is limited on the north and west by the 

 Roan, or Book Clifis, and their foot-hills, which follow the 

 general course of the river. These cliflTs rise from the valley 

 in a succession of steps to a height of about 4000 feet above 

 it, or 8000 to 8500 above the sea. 



From its crest, this plateau (for the Book Clifi's are but the 

 southern escarpment of a plateau) slopes to the N.N.E, at 

 an angle of not more than 5. It extends from the Wahsatch 

 Mountains on the west to the foot-hills of the Park Range on 

 the east, and presents every where the same characteristics. 

 The Green River crosses it, flowing in a direction exactly the 

 reverse of the dip. It borders the Grand on the north for 



