36 INSTRUCTIONS TO LIEUTENANT DONELSON. 
It is impossible to give more definite instructions than those indicated in my letter of day 
before yesterday, and given in this note. Much is left, of necessity, to the judgment of the 
officers charged with the work. It involves a constant exercise of judgment and a careful 
study of every new fact. ‘The country is not known except in a general way; but enough 
is known to say that the approaches to Cadotte’s Pass must be over a large space of country, 
and the examinations must be such that the main features shall be given with accuracy. 
When Mr. Tinkham gets in, he can at once join you, giving to the region you pass over in 
advance a careful examination for facts and general views of construction. With his work, and 
that of Mr. Lander and Lieut. Grover, the connexion from Milk River valley with your work 
will be complete. 
] wish you to throw yourself into this work with your whole force. It is important that not a 
day should be lost. 
As regards Lieutenant Mullan, unless his services are indispensable, he should go to the Flat- 
head camp, reaching St. Mary’s village by a new and more southern pass. The force placed at 
his disposal must of necessity be small. Including one Indian (Piegan) and Mr. Rose, (Mr. 
Culbertson’s storekeeper) I cannot assign more than twomen. Yet it must be certain that he 
can be spared from the magnetic observations and from the main train. He will, at all events, 
find his field on reaching the St. Mary’s village. 
You must go in advance, and if possible to-morrow. The main train should move not longer 
than four days after you. It will consist of twelve mule wagons, not loaded more than 1,200 
pounds each. 
I shall push all my business through to-day, and have not the time to consult I desire. When 
you come in, and come early, have your programme complete for the advance party, and I will 
decide at once. 
* * * * * * * * * * * 
[Here follow some unimportant paragraphs, relating to duty for next day, &c.] 
Truly yours, 
ISAAC I. STEVENS, 
Governor of Washington Territory, in Charge of Exploration. 
No. 8. 
Forr Brenton, Upper Missouri, * 
September 7, 1853. 
Str: You are placed in charge of the survey of the railroad route from this point through 
Cadotte’s Pass to the St. Mary’s village, and your force will consist of the odometer party, in 
charge of Mr. Lambert, assisted by Sergeant Collins ; the astronomical party, in charge of Mr. 
Stevens, assisted by Sapper Roach ; the magnetic party, in charge of Mr. Doty, assisted by 
Sapper Wilson ; Dr. Suckley, the surgeon and naturalist of the expedition, assisted by Sapper 
Horner ; the meteorological party, in charge of Mr. Moffett, assisted by Mr. Burr and the trained 
sappers of your detachment ; Mr. Tinkham, estimating engineer ; Mr. Osgood, the disbursing 
quartermaster and commissary agent and acting quartermaster and commissary of the party, 
and especially in charge of the baggage and supply train, with Sergeant Higgins, Corporals 
Coster, Simpson, and Pierson, assistant wagon and pack-masters; Sergeant Lindner in command 
of dragoons, Corporal Causser with the mountain howitzer, and fourteen non-commissioned 
officers and men of the dragoon detachment ; Mr. French and Mr. Morgan, artificers ; Bashall, 
the blacksmith, Meckleback, saddler, and twenty-seven quartermaster’s employés, &c. 
You will form an advance party, consisting of the odometer party, the estimating engineer, 
(as soon as he shall have returned from his reconnaissance of the Three Buttes,) and Mr, Adams, 
