PASS THROUGH THE BITTER ROOT MOUNTAINS. 539 
by a high-rolling prairie country on the east, and directly with the valleys of the Little Blackfoot 
and Hell Gate rivers on the west. 
During my examinations, my time was devoted more to reconnaissances than to detail surveys. 
This was necessary, owing to the very meagre and unreliable information that was at our disposal 
from any and every source. Had a detail survey been made over one route, to the exclusion of 
a second or more in that particular region, it would not, I fear, have given satisfaction either to 
the department or to yourself; and I am confident that I should not have been enabled to give a 
decided and positive opinion as to the superiority of one over another; for had the time been 
spent in examining minutely one particular line, and it, in the end, been found impracticable, it 
might have been possible that a better route was to be found to our right or our left, and yet we 
be perfectly unconscious of it. 
Taking the view, therefore, that the mountains should be examined and reconnoitred in a 
general manner, in order to discover and explore such passes as might exist, I devoted my time 
and labors in carrying out this plan. In so doing, I went through several passes, and this one in 
the Rocky mountains I now refer to I deem the most practicable of all. 
But, owing to the want of proper instruments, after its discovery I was not enabled to give its 
position astronomically or its accurate profile. Suffice it to say, however, it is the best pass I 
have yet found in the mountains, with excellent approaches on either side. This pass extends to 
the Bitter Root and St. Mary’s valleys, by the Hell Gate defile. The route then followed is by 
the Bitter Root valley to the mouth of the St. Regis Borgia creek; thence up this creek to the 
divide of the Bitter Root mountains, to the north gut of the Coeur d’Alene lake; thence either by 
the Spokane river to the Columbia, or by crossing the two guts of the Coeur d’Alene lake to 
Snake river, at or near its great bend in the vicinity of Fort Wallah-Wallah, or avoiding the 
Snake river i toto by striking the Columbia over a high-rolling prairie country to the mouth of 
the Yakima. 
I deem an instrumental survey of these two passes to be vitally necessary, in order to show 
their relations to the passes already explored and surveyed, and at the same time show their 
advantages as compared to the passes already examined through the Rocky and Bitter Root 
ranges of mountains; and I further deem them essentially necessary, in view of a final report upon 
this great and momentous question. 
Were there no other consideration to induce .this, the fact alone that the barometric profiles of 
the expedition were lost while on their way to Washington city, is, in itself, a sufficient argument 
to have a more thorough examination made in that interesting region of country. 
Owing to the action of the Indian Department, in conformity to an act of the last Congress, 
authorizing it to hold a council with the Indian tribes at Fort Benton during the coming season, I 
would suggest the following plan, which might be submitted to the Hon. Secretary of War for his 
approval or disapproval. 
Presupposing that a large force will be present at the council, a party of one officer and four 
employés might be authorized to accompany it for protection as far as the falls of the Missouri 
from St. Louis. A party so starting and so organized could determine the latitude and longitude 
of those points of the Missouri to the falls not yet determined, as well as ascertain the heights 
above the sea of the principal points along the route; thus giving the profile from St. Louis to the 
Great falls of the Missouri. The party then starting from the falls would be enabled to make a 
detail and instrumental survey of the two passes I refer to, even so far as to running a line of 
spirit-levels through the passes, with their approaches on either side. Thus taking advantage of 
this council to be held at the falls of the Missouri, a party of five men would be complete in itself, 
and would be enabled to develop the same facts that it might take a party of twenty-five or 
thirty—the smallest party that could be sent with safety into that country—supposing them to 
take advantage of the presence of the men who will necessarily be at the council. 
Taking into consideration the exceedingly economical and small scale upon which such an 
