68 APPENDIX TO REPORT OF THE SECRETARY, 



for topographic work was that embraced in the eastern half of atlas 

 sheet 75, and that portion of sheet 86 lying east of the Green and 

 Colorado Rivers, an area of about 10,000 square miles. The most re- 

 markable topographic feature of this region is a bold escarpment facing 

 the south, and extending from the western, far beyond the eastern limit 

 of Mr. Graves' work. This is known as the Book Cliffs. At the foot 

 of this escarpment lies a narrow valley, through which passes the only 

 practicable route of travel between Central Utah and Western Colorado. 

 South of the valley the whole region is cut by a labyrinth of canons, 

 formed by the Grand, Green, and San Eafael Elvers and their tribu- 

 taries. This region is one of the most inhospitable and inaccessible in 

 the territory of the United States. It is characterized by extreme 

 aridity, and some portions are cut by many narrow gorges, forming 

 " alcove lands." In other portions are found hills of naked sands and 

 clays, regions of bad lands, bold cliffs, towering monuments, hills of 

 drifting, glittering sands, and deep, tortuous caSons, which give to the 

 landscape a strange and weird appearance. 



The Book Cliffs rise to an average altitude above their base of 3,000 

 feet, and about 8,500 feet above the sea-level, and the country from the 

 southern crest inclines gently northward to the valleys of the White and 

 Uinta Rivers. This gigantic terrace, called the Ta-vd/-puts Plateau, is 

 cut in twain from north to south by the profound gorges through which 

 the Green River runs, known as the Caiion of Desolation and Gray 

 Canon. The drainage of the plateau is northward from the brink of 

 the cliffs through deep, narrow canons for many miles, but at last all 

 these enter Caiion of Desolation a few miles from its head. North of 

 the Ta-vaputs Plateau are the valleys of the White and Uinta Rivers. 

 Nearly all the former and a large portion of the lower course of the 

 latter are within the boundaries of Mr Graves' work. 



Over the whole district assigned to Mr. Graves he extended the 

 secondary triangulation. Owing to the peculiar topography of the 

 country, his stations will average about twelve miles ajmrt. He also 

 made a connected j^lane-table maj) of the whole area, and complemented 

 his work with orographic sketches. 



In the southern i)ortion of the area surveyed by Mr. Graves, consider- 

 able bodies of irrigable lands are found along the Grand, Green, San 

 Rafael, and Price Rivers, and in the northern part, along the Green 

 River and in the valleys of the Uinta and White Rivers, are other large 

 tracts, on which the waters of the streams named can be conveyed at 

 slight cost. Mr. Graves determined the extent, character, and location 

 of these lands, and the amount of water carried by the streams through- 

 out the area embraced in his work. 



On the Ta-vdputs Plateau are small forests of pine and fir, but gener- 

 ally Mr. Graves' district possesses no more timber than sufiQcient to 

 meet the future local requirements of actual settlers. 



ToiJograiJliic work by Mr. liensliaice. — The district assigned Mr. Ren- 



