GEOGRAPHY OF NORTH AMERICA. 213 



posit, probably of Miocene age, astonishingly rich in insect 

 remains, many of them beautifully preserved. During the 

 past year about 20,000 insects have been exhumed from this 

 single locality; and scarcely an impression has been made 

 upon the quarries, although perhaps more labor will hereaf- 

 ter be required in working them. In company with Profess- 

 or Lakes, of Golden, they made as careful a survey of the 

 basin in which they occur as their short stay permitted, and 

 estimate the insect -bearing shales to have an extent fifty 

 times as great as the richest localities known in Europe. 



The geographical and geological survey of the Rocky 

 Mountain region under Major Powell, to which, from its 

 departmental connection with Dr. Hayden's survey, atten- 

 tion is next invited, confined its operations the past season 

 almost entirely to the central portion of Eastern Utah, an 

 area containing about 16,000 square miles, embraced be- 

 tween 38 and 4030'N. lat. and between 109 30' and 112 

 W. long. Nearly the whole of this region is drained by the 

 Green River and its affluents, before it unites with the Grand 

 to form the Colorado, and is one of the most arid, inhospita- 

 ble, and inaccessible in the country. It is an elevated plateau, 

 cut by a labyrinth of canons and narrow gorges, and covered 

 in many parts by hills of naked sand and clays. The west- 

 ern portion, however, includes broad valleys, abrupt ranges 

 of mountains, and one plateau of considerable extent, having 

 an average elevation of 8000 feet. The valleys, which con- 

 tain large areas of excellent land, run north and south, sepa- 

 rated by three ranges of mountains, rising in their highest 

 peaks to from 10,000 to 12,000 feet, and are drained by 

 streams flowing westerly into Utah Lake. 



With Pleasant City, a little town about one hundred and 

 twenty-five miles south of Salt Lake City, as a base of sup- 

 plies, three parties were organized one for geodetical and 

 two for topographical-work. The triangulation was extend- 

 ed over the entire area selected. The work rests upon base- 

 lines established in former years near Kanab and Gunnison, 

 Utah, and was connected on the east with the triangulation 

 points established by Hayden's Survey, and on the north 

 with those of the Fortieth Parallel Survev under Mr. King: 

 On account of the rumored hostility of the Utes in a portion 

 of the district (rumors which proved groundless), the trian- 



