LETTER TO THE SECRETARY OF WAR. 619 
two flourishing settlements. It is probable the line of railroad will run either to Port Gardner or 
to some point north, as Bellingham bay. I will have established at the falls a depot of provisions 
and two or three men, and I shall send up a party into the pass from this side, which will prob- 
ably meet you. They may run the line to Bellingham bay. Make the falls a point in your 
route. Should your animals be exhausted and unfit for further service, send them by one or two 
men to Steilacoom, and take canoes and go down the river. It is about one day down the river 
to its mouth, and a day and a half toOlympia. If your animals are strong enough, come through 
all the way by land. I want you to see how railroads and wagon roads can be brought down 
from the pass to Steilacoom, including, if practicable, a line to Elliott’s bay. This line is said to 
be impracticable. I will send forage to the falls. Write me word of your departure from 
Wallah-Wallah, and take pains to have it forwarded promptly. 
Orrice NortHern Paciric Ramroap ExpLoraTION AND SurRVEY, 
Olympia, Washington Territory, December 30, 1853. 
Str: I have the honor to report the arrival of Lieutenant Arnold, from his route by the 
northern trail to Colville, and thence by the line of the Columbia river to Wallah-Wallah, and 
acknowledge his energy and promptitude in making, at this late state of the season, valuable 
contributions to our knowledge of the country passed over by him. 
Lieutenant Arnold, under instructions from Lieutenant Donelson, left his camp at the crossing 
of Clark’s fork, west of the Pend d’Oreille lake, on the 24th of October, witha select party of six 
men, an Indian guide, and eighteen animals, and reached Colville on the 30th. Here, in pursu- 
ance of instructions left by me, he ascended the Columbia in canoes and found the mouth of 
Clark’s fork about two miles north of the 49th parallel, and thus settled a disputed question of 
geography. His route from Colville to Wallah-Wallah was by the Grand Coulée. The follow- 
ing extracts from his reports to me, of this date, will give a general view of his route. 
“Tn accordance with your instructions, I ascended the Columbia to the 49th parallel, which 
was found to cross the Columbia about two miles south of its confluence with Clark’s fork. My 
observations in connexion with the survey of this portion of the river were confined to a narrow 
belt of country, included between two parallel ridges of mountains, whose general directions were 
north and south. This belt was level, gradually ascending to the north, well wooded, and, even 
at this late season, covered with fine grass; the soil alluvial and sandy. The mountain ranges 
are a continuation of those seen along the western bank to the south, to the east presenting one 
uniform unbroken outline, the first pass being at Colville; the current of the river rapid in the 
channel, with innumerable eddies and whirlpools along its banks; its bed rocky. Having com- 
pleted the survey of the Columbia north of Colville, I left the latter place on the 14th of Novem- 
ber and marched along the east bank of the Columbia for six days—distance, about 110 miles; 
the trail over a level and wooded country, to the Spokane river, and from the latter place to 
where the Columbia makes the great bend to the west, and from here to the mouth of the Grand 
Coulée, exceedingly rough and dangerous; the country to the east and south, after leaving the 
high banks of the river, undulating. At this point, 110 miles from Colville, I proceeded south 
from the river, and immediately made an ascent of about 100 feet, when I came to the Grand 
Coulée. This mighty avenue, about 15 miles to the south, and three to six in width, has a gradual 
ascent to the south. Its sides are one perpendicular mass of molten rock, about 800 feet in 
height, and on a level with the grand plain of the Spokane. With the exception of a few trees, 
seen in this coulée, there is no timber between this coulée and the Columbia. After marching 30 
miles, I entered the most southern and second coulée in size. Its general appearance was like 
the former, and it was about six miles in length, with a more westerly direction. The country 
between these coulées generally level, with the exception of innumerable smaller ones, like those 
already mentioned. From the southernmgst coulée to the Columbia the country is level and 
