LETTER TO THE SECRETARY. XT 



sea-level) to be dignified with the name of mountains, and are bare of 

 timber and grass-covered. All this section is fine grazing land, and i i 

 the valleys are large areas of arable land. 



North of the Snake are several fine valleys, well watered from tin 

 snow-fields of the high mountains, among which are Pierre's and Jack- 

 son's Holes ; but the mass of the country is made up of mountains. A s 

 a rule, the valleys are narrow, mere canons in very many cases. Tin- 

 mountains are everywhere heavily timbered with pine and spruce. 



During the season, Mr. Bechler occupied 60 stations, and measured 

 7,340 horizontal and 5,700 vertical angles. 



The area assigned to the Green Eiver division, in charge of Mr. Henry 

 Gannett, lay between the meridians of 109° 30' and 112° 00' and the 

 parallels of latitude of 41° 45' and 43° 00', being directly south of that 

 of the Teton division. This district includes the northern half of the 

 Green Eiver Basin, nearly all the drainage area of the Bear, and sev- 

 eral large branches of the Snake, comprising portions of the three 

 Territories of Wyoming, Idaho, and Utah. The country being especially 

 well adapted to this class of surveying, work was pushed very rapidly, 

 so that, after finishing his district, Mr. Gannett was enabled to carry the 

 work westward over the valleys of the Portneuf and Malade, with their 

 bounding ranges. 



With the exception of the Green River Basin, which is a broad, flat 

 expanse of sage and grass, the country consists of a succession of par- 

 allel ranges of mountains, with the normal Rocky Mountain trend, sep- 

 arated by broad valleys. The valleys are fertile and easily irrigated, 

 while everywhere there is a bountiful supply of water. The average ele- 

 vation of these valleys is from "4,000 to 6,000 feet, while the mountain.-* 

 rise to heights ranging from 8,000 to 11,000 feet. 



The lower mountain-ranges are grass-covered, while the higher ones 

 are well timbered, in some cases even densely timbered, with heavy 

 spruce and pine. The area of irrigable land is, by a rough estimate, ten 

 per cent, of the district, while at least three-fourths of it is suitable for 

 grazing. In surveying this area, Mr. Gannett made 347 stations of all 

 grades of importance, building monuments on 53 of the principal ones 

 for future reference by the land surveys, or other purposes. 



The district assigned to the Sweetwater division, under Mr. George 

 B. Chittenden, lay between meridians 107° 00' and 109° 30' and parallels 

 41° 45' and 43° 00', being east of that last described. It includes the 

 southern half of the Wind River Range, the valleys of Wind River and 

 the Sweetwater, with the Sweetwater Mountains and the desert-like 

 plateaus about the continental divide south of the latter. Of this area 

 nearly all or between 10,000 and 11,000 square miles were surveyed. 

 Of this district, a rough estimate makes five-eighths desert country, two- 

 eighths mountainous, of value only for its timber, or, hypotheticallv. for 

 its mineral contents, and one-eighth only valuable as pasture or agricul- 

 tural land. In surveying this area Mr. Chittenden made nearly 200 



