APPENDIX TO EEPORT OF THE SECRETARY. 69 



shawe was that embraced in the western portion of atlas sheet 75, an 

 area of about 6,000 square miles. The eastern portion of this area is a 

 broad table-land called the Wasatch Plateau, having an average eleva- 

 tion of about 9,500 feet, cut by deep valleys and drained from its very 

 western edge toward the east by the Fremont, San Eafael, and Uinta 

 Elvers. The western portion includes broad valleys, abrupt ranges of 

 mountains, and one plateau of considerable extent. The principal val- 

 leys in this part are the San Pete, Juab, and Utah all having a general 

 northern and southern trend, an average elevation of about 5,000 feet, 

 and all are drained by the San Pete River and the streams flowing into 

 Utah Lake. The mountain-ranges standing between the valleys are the 

 Wasatch, rising in its highest peaks to 12,000 feet, the Lake Mountains, 

 and the Tintic Hills, each reaching an altitude of nearly 7,500 feet. 



The tableland called Gunnison Plateau has an area of about 750 

 square miles, and an average elevation of 8,000 feet. It is bounded on 

 three sides by almost vertical walls, and is extremely rugged and diffi- 

 cult to traverse. 



There is but little irrigable land in the eastern portion of Mr. Een- 

 shawe's district, but the broad valleys of the western portion contain large 

 areas of excellent lands, and the numerous streams furnish a good sup- 

 ply of water. Mr. Eenshawe determined the volume of water in every 

 considerable stream, as well as the extent and localities of the irrigable 

 lands, throughout his district. 



On the plateaus and mountain-ranges are large quantities of excellent 

 timber. On the head- waters of Price Eiver and on Huntington Creek 

 are extensive beds of coal, and on that portion of the Wasatch Eange 

 included in Mr. Eenshawe's district are deposits of silver and galena. 



Mr. Eenshawe extended the secondary triangulation over the whole 

 district assigned him, making stations at an average distance of about 

 eight miles, and measuring all the angles of nearly every triangle in the 

 extension. He also made a connected plane-table map of the whole 

 area, and complemented his work with a complete set of orographic 

 sketches. 



Hypsometry.— The hypsometric work of this season rests on a primary 

 base established at the general supply and rendezvous camp at Mount 

 Pleasant, and connected by a long series of observations with the sta- 

 tion of the United States Signal Service at Salt Lake City. At the base- 

 station observations were made with mercurial barometers four times 

 each day, and for eight days during the month hourly from 7 a. m. to 9 

 p. m. Mercurial barometers were carried by each field-party and obser- 

 vations made to connect every camp with the base-station. All the 

 geodetic points and topographic stations were connected by observa- 

 tions with mercurial barometers either with the camps or directly with 

 the base-station or both. All the topographic stations were also con- 

 nected with each other by angulation, and from these stations the alti- 

 tudes of all located points were determined by the same method. 



