INSTRUCTIONS TO LIEUTENANT DONELSON, 37 
assistant artist ; an assistant from the meteorological party, a small detachment of dragoons, 
with the necessary employés of the quartermaster’s department, two wagons, rations for fifteen 
days, will move forward at once towards Cadotte’s Pass, moving slowly, covering the ground 
with great care from the dividing ridge east of the Big Teton to the Missouri river, and in- 
cluding a rapid reconnaissance of the falls of the Missouri river. 
The approaches to Cadotte’s Pass must be examined with care, and full information gained as 
to river crossings and side approaches. The space to be covered, at first large, will undoubtedly 
narrow towards the entrance to the pass. Advantage must be taken of hills to gain views of 
country. Small detached parties of one, two, or at most three men, must be thrown out for 
purposes of reconnaissance. In the pass the lateral valleys and passes should be examined to 
the extent of the force at your disposal. More definite instructions cannot be given. The 
field will open and the right methods will be suggested as you advance. Much must be left, of 
necessity, to your own judgment. I refer you, in relation to this matter, to my letter of this 
morning, which will be considered as a portion of these instructions, and in which my views are 
given as to the method of conducting operations. 
For information as to the details of the work, I refer you to my printed instructions, to the 
written instructions addressed to and in possession of the chiefs of parties, and to the methods 
actually in use since your connexion with the main party. 
The supply and baggage train will move forward on the 11th or 12th instant, in charge of 
Mr. Osgood, and the marches will be so arranged between the two portions of the command, 
as that the whole shall be brought together at the foot of the first dividing ridge, and where 
the greatest obstructions to the passage of wagons are said to be found. All the baggage will 
be carried in wagons, and the train will consist of twelve mule teams and one ox-wagon. 
On reaching the point where serious difficulties may occur to the passage of wagons, an effi- 
cient pioneer party should be organized, kept well ahead to remove obstructions, and prepare 
for the passage of the train. Ample supplies of rope and tackle should be provided. You are 
instructed to direct your energies to the passage of the train, though not to involve serious 
detriment to the prosecution of the survey. All the pack-saddles will be taken along to pro- 
vide for the possible necessity of abandoning the wagons. The wagons will not, however, be 
abandoned without my direct order, and you are authorized, when, in your judgment, the task 
of pushing through the wagon train shall endanger the operations of the survey, to make a report 
in writing to me to that effect, and to turn over the train to Mr. Osgood, taking the rations 
necessary for reaching the St. Mary’s village, and leaving to me the responsibility of deciding 
upon the question of continuing the effort to get the train to the St. Mary’s. In drawing 
rations, however, you will leave with the train at least double the amount taken for the party 
you may organize under your immediate charge for the survey. I cannot authorize, however, 
the separation of the party, and placing the entire responsibility of the train with Mr. 
Osgood, without your written report, referred to above, addressed to me, and placed in his 
hands. That report will authorize Mr. Osgood to take such measures for the care of the train 
and animals as, in his judgment, may be necessary. 
On reaching the St. Mary’s village, you will rest your animals and await my arrival—con- 
forming, however, to instructions you may receive from Captain McClellan. It is probable that 
Lieutenant Mullan may reach that point not long after your arrival, bringing excellent Flat- 
head guides, acquainted with the several passes to the Hudson’s Bay posts on the Columbia 
river, and to Fort Hall. No time should be lost in gaining every possible information as to 
routes. In case of a depot not having been established at the St. Mary’s village by Lieutenant 
Saxton, Dr. Evans, the geologist of the expedition, has instructions to bring up supplies from 
the Dalles for the service of the parties that may operate from the St. Mary’s village. 
It is my intention to establish at the St. Mary’s village a winter post in charge of Lieutenant 
Mullan, to operate in the passes of the mountains till driven out by snow, and then to explore 
the lateral valleys and passes. Its establishment is essential to secure success to the contem- 
