9 



The completion of the exploration of the interior of Nobnuska, about 

 the sources of the Yellowstone, Lieutenant Warren thinks conld be 

 most advantageously and economically made by an expedition organ- 

 ized to remain at least two years in the field, and the cost of this he 

 estimates at $G0,000. This exploration has been a favorite object 

 with him, and his previous experience, and his knowledge of the 

 Indians and character of the country, would enable him to accomplish 

 the work with economy. 



The highly crcditiible manner in which the explorations heretofore 

 intrusted to him have been conducted, under many embarrassments, 

 dilBculties, and dangers, prove him to be peculiarly well qualified for 

 the task. 



A detailed plan for the execution of the work will be found in the 

 report. 



IV. — THE MILITARY ROAD FROM FORT BENTON TO FORT WALLA-WALLA. 



The opening of the military road from Fort Benton, on the Missouri 

 river, to Fort "Walla- Walla, on the Columbia river, for which there was 

 an appropriation of $30, 000, was assigned to Lieutenant John Mullan, 

 2d artillery, on the 12th of last March. On the 25th of May Lieutenant 

 Mullan had organized his working party and left Fort Dalles, on the 

 Columbia river, for Fort Walla- Walla, when intelligence was received 

 by him of the commencement of hostilities by the Indian tribes 

 occupying the regions through which the route he was about to open 

 passes. The party was accordingly disbanded, and Lieutenant Mullan 

 joined Colonel Wright's command, as topographical officer, and in that 

 capacity, and in command of a party of friendly Indians, participated 

 in the campaign upon the Spokane plains. The appropriation was 

 entirely inadequate to the object for which it was designed, and to 

 open a road of similar permanency of character with the military 

 roads in the United States Territories would require a very much 

 larger sum. No estimate of this has been made, but it mav be 

 assumed that it will not be less than the amounts expended on equal 

 lengths of route on the wagon roads to the Pacific in other latitudes, 

 for which appropriations have been made. 



V. — OFFICE WORK. 



In addition to supplying the general map of the United States 

 Territories for military purposes, special maps of the theatres of 

 operations have been furnished to the troops engaged in the field. 

 Maps of each of the military departments are being prepared. Upon 

 the general map of the United States Territories west of the Missis- 

 sippi, Lieutenant Warren has laid down the approximate boundaries 

 of the various Indian tribes that occupy the country. Copies of this, 

 printed in colors, so as to exhibit the location of each tribe, showing 

 also the limits of the military departments, and positions of th« 

 military posts, will, it is believed, be found useful to the War Depart- 

 ment and the army, and will matorially aid those not familiar with 



