6 



The region explored is pronounced to bo of little agricultural value. 

 Cretaceous coal was found near the Moquis towns. 



The examinations of Lieutenant Ives confirm the opinion of Captain 

 Whipple as to the railroad practicability of the line from the Big 

 Sandy to the Colorado river, which is shorter than the line down Bill 

 Williams' Fork by ninety miles, and less costly by six million dollars. 

 The changes effected by the adoption of this line, in the length and 

 cost of the whole route, will be found on pages 36 and 37 of the con- 

 clusion of the official review, volumeVII of the Pacific Railroad Report. 

 This is the only modification of the railroad route of the 85th parallel 

 introduced by the explorations of Lieutenant Ives and the examina- 

 tions made by Mr. Bealo when opening the wagon road from Port 

 Defiance to the Colorado river. 



The explorations conducted by Lieutenant Ives Avere attended by 

 circumstances of more than ordinary difficulty, and the successful 

 execution of the duties assigned to him is liighly creditable to himself 

 and party. 



III. EXPLORATIONS IN NEBRASKA. 



The return, in November last, of the expedition commanded by 

 Lieutenant G-. K. Warren, Topographical Engineers, after the suc- 

 cessful execution of the duties intrusted to him of reconnaissance and 

 exploration in Nebraska, has been already reported. The maps have 

 been completed, all the necessary calculations of the astronomical and 

 barometrical observations made, and the reports in relation to the 

 different objects of the expodition are in an advanced state. 



The principal objects of the expedition were to ascertain the best 

 route by which to continue to the South Pass the military road now 

 constructing from the Mississippi river to Sioux City, on the Missouri, 

 and to examine in this connexion the valley of the Loup Fork of the 

 Platte, and that of the Niobrara, and to make such reconnaissance of 

 the Black Hills about the sources of the Big Shyenne as circumstances 

 would permit, to determine their character, especially Avith reference 

 to the future military operations that may be carried on in this Terri- 

 tory. In accomplishing these objects, the expedition would obt^un 

 information of the character and resources of the country, its adapta- 

 bility to settlement and cultivation, and would develop its geography 

 and geology along the routes pursued, nearly all of which were pre- 

 viously unexplored by Avhite men. 



The preliminary report of Lieutenant Warren is hereAvith pre- 

 sented. The routes reconnoitred and mapped in 1857 are from Sioux 

 City to the mouth of Loup Fork; thence up this stream to its source 

 in the Sand Hills; and thence by the Niobrara to Fort Laramie. From 

 this point the party proceeded north and carefully examined the 

 Black Hills, and, returning to the Niobrara, explored this stream to 

 its junction with the Missouri; and also a route from the mouth of 

 Turtle Hill river to Fort Randall. Finally, the road from Fort Randall 

 to Sioux City Avas surveyed. 



With the report on these routes Lieutenant Warren combines that 



