50 



to this duty, and will proceed with his party by the steamer St. Mary's' 

 to the point above indicated. 



On his return, Lieutenant Warren will procure a sufficient number 

 of Mackinac boats, for the transportation of his party, stores, &c., to 

 enable him to effect a thorough examination of this part of the river. 



II. The commanding officer of the 2d infantry will select an efficient 

 party from his regiment, consisting of two non-commissioned officers 

 and fifteen men, to report to Lieutenant Warren as his escort. They 

 will be furnished with three months' provisions, equipage, &c. 



III. The assistant quartermaster at Fort Pierre will furnish the 

 necessary transportation, and such supplies as Lieutenant Warren 

 may be entitled to from his department, for the proper execution of 

 these instructions. 



By order of Brevet Brigadier General Harney. 



A. PLEASONTON, 

 Coptain 2d Dragoons, Acting Assistant Adjutant General 



REPORT. 



CHAPTER I. 

 Routes explored, and main incidents affecting their extent and dw^atic/z. 



In presenting the following report of explorations in Nebraska, 

 made by me in the year 1857, I shall include also my previous recon- 

 naissances in that Territory in the years 1855-56, while attached to 

 the staff of Brevet Brigadier General W. S. Harney, commanding 

 the Sioux expedition. As, at this time, a complete narrative of these 

 cannot be made, I shall only mention the routes pursued and the 

 nature of the examination, and then give what I consider the most 

 prominent results. 



A report of the explorations made in 1855, and map of the routas 

 pursued by the bioux expedition, have already been published by the 

 United States Senate in a small document called "Explorations in 

 the Dacotah Country." During that year routes were examined from 

 Fort Pierre to Fort Kearney ; from Fort Kearney to Fort Laramie, 

 along the Platte river; from Fort Laramie to Fort Pierre ; and from 

 Fort Pierre to the mouth of the Big Sioux river. 



In 1856 I started from St. Louis for Fort Pierre, in the middle of 

 April, accompanied by my assistants, Messrs. W. H. Hutton, J. H. 

 Snowden, and F. V, Hayden, on board Captain Throckmorton's steam- 

 boat Genoa. During our passage up the Missouri we made a careful 

 sketch of. the river above the southern boundary of Nebraska by 

 means of compass courses, and distances estimated from the rate of 

 travel of the steamboat, and by astronomical observations for latitude. 

 The elevated position of the pilot-house of the steamboat, which the 

 politeness of the captain allowed us to occupy, afi'orded advantages 

 for gaining a knowledge of the river, the extent of the sand bars, and 



