LETTER TO LIEUTENANT ARNOLD. 
6Y 
Cascade range, and to a most admirable development of the unknown geography of the region 
eastward to the Columbia, as showing the unsurpassed skill and devotion which has character¬ 
ized the chief of the division and all of his associates. 
To Lieutenant Donelson and his command thanks have already been tendered for their pre¬ 
vious services. But special commendation is now due for the constancy and success which have 
crowned their labors on their difficult line of Clark’s fork, from the St. Mary’s village to this 
point. The detached party under Lieutenant Grover, engaged in the survey of the upper Mis¬ 
souri, and about to cross the mountains with a dog train; the parties under Lieutenant Arnold, 
now at Fort Colville; under Lieutenant Mullan, now exploring the route from the St. Mary’s 
valley to Fort Hall; under Dr. Suckley, on his way in a boat, with two men, from the St. Mary’s 
valley by that river, Clark’s fork, and the Columbia, to Fort Colville; Mr. Tinkham, engaged in 
the exploration of the Marias Pass and the broad Flathead trail; and Mr. Doty, in charge of a 
meteorological party at Fort Benton, must not be forgotten. They have all developed ability of a 
high order in the progress of the exploration. No one doubts that success will crown their 
labors. 
The chief of the exploration would do injustice to his own feelings if he omitted to express 
his admiration for the various labors of Mr. Stanley, the artist of the exploration. Besides 
occupying his professional field with an ability above any commendation which we can bestow, 
Mr. Stanley has surveyed two routes—from Fort Benton to the Cypress mountain, and from the 
St. Mary’s valley to Fort Colville over the Bitter Root range of mountains—to the furtherance 
of our geographical information, and the ascertaining of important points in the question of a 
railroad; and he has also rendered effectual services in both cases, and throughout his services 
with the exploration, in intercourse with the Indians. 
Our labors are near their conclusion for the present season, and it only remains to go into 
quarters. The two divisions, under the respective commands of Captain McClellan and Lieu¬ 
tenant Donelson, will proceed to the Columbia barracks by way of Wallah-Wallah and the 
DalleSj and then await instructions as to the discharge of their men and the arrangements 
for the office-work. The animals will be left at Wallah-Wallah and the Dalles, in the charge 
of trustworthy men, to be cared for during the winter, in readiness for operations in the spring. 
ISAAC I. STEVENS, 
Governor of Washington Territory , in Charge of Exploring Expedition , &c. 
No. 10. 
Camp Washington, 
Tioelve Miles South of Spokane House , October 29, 1853. 
Sir: We met the party of Lieutenant Donelson at this place yesterday, and from him I 
learned that you probably reached Colville yesterday. Besides the instructions which I left 
there for you with Mr. McDonald, I have only to suggest that in your route to Wallah-Wallah 
it will be well to examine the Grande Coulee. It is left free with you, however, to decide, 
should the lateness of the season or the condition of your animals make it advisable, whether 
you will take this route or pursue the best known trail to Wallah-Wallah, concerning which you 
can receive full information from Mr. McDonald. You are authorized, should your judgment 
dictate it, to leave your animals at Colville, making arrangements with McDonald for their safe¬ 
keeping; and, in connexion with Dr. Suckley, to descend the Columbia river in a boat, making 
the best survey you can. I send you a memorandum of points, in the line of the Columbia, 
particularly requiring attention, which has been proposed by Captain McClellan. Although it 
is desirable to meet Dr. Suckley, and with him confer upon your own and his future operations, 
it must not be done at the expense of too much time; and you are authorized, should you not 
meet him at Colville on your return from the upper Columbia, to move at once to Wallah- 
