282 FROM MOUTH OF CLARK’S FORK TO WALLAH-WALLAH. 
20. Report OF DR. JOHN EVANS, OF HIS ROUTE FROM FORT BENTON TO THE LOWER COLUMBIA. 
[This paper, sent from Washington Territory, where Dr. Evans was still employed in the field when the report of Governor 
Stevens was submitted, was lost on the route. ] 
21. Report oF LIEUTENANT RICHARD ARNOLD, U. S. A.» OF HIS ROUTE FROM THE MOUTH OF 
CLARK’S FORK, BY FORT COLVILLE, THE GRAND COULEE, AND THE MOUTH OF SNAKE RIVER, TO 
WALLAH-WALLAH. 
Otympia, W. T., February 5, 1854. 
Sir: In compliance with your instructions, dated October 23, 1853, I have the honor to sub- 
mit the following report, accompanied with a map and profile of the route travelled by the party 
under my command. 
Hearing of your arrival and departure from Fort Colville with Captain McClellan and party, 
I moved in advance of my command, then encamped about twenty miles from the fort, to learn if 
any instructions had been left by you that would conflict with those previously given by Lieu- 
tenant Donelson, U. 8. A. Receiving the above named, I returned and marched my party to 
Colville, encamping on the east bank of the river, about half a mile above the fort. Before 
returning to my camp, I despatched an express to Pend d’Oreille mission with the letters, one to 
the reverend father, the other to Dr. Suckley. The latter one, by some inconceivable mistake, 
returned to me, but the other had the desired effect. ‘The day after my arrival at the fort being 
a holiday, I was not able to obtain the necessary transportation for the river trip until the 3d of 
November. I then succeeded in hiring two canoes and four Indians. It was my wish to com- 
mence a series of barometrical observations at the 49th parallel, or thereabouts, to determine the 
fall of the river from that line to the ocean. The want of transportation prevented. I then had 
a series of observations taken at my camp near the fort. Leaving my camp at 2 p. m. on the 3d 
of November, I commenced the ascent of the river, taking one man to run the compass lines and 
take topographical notes of the country. The swift current, numerous small rapids, and many 
unforeseen accidents, made the ascent very slow, but at noon of the fourth day I arrived at a 
point about three and a half miles above the mouth of Clark’s fork. Here I obtained an obser- 
vation, the first since my departure from Colville; this placed me in latitude 49° 3/ 25”.9; thus 
showing a material error in the maps in my possession. This observation’ having been taken 
with sextant, may not be absolutely correct, but I feel confident that all future surveys will not 
find it far out of the way. Ithen embarked and run down with the current, passing through 
the rapid Little Dalles, and arrived at my camp on the 8th, having been absent five days and 
ascended the river thirty-five miles. The weather during the entire trip was very unfavorable. 
The second and third days after my departure, the snow fell to the depth of six inches, which 
made the travelling very uncomfortable, and it was with the greatest difficulty that I could keep 
my Indians from stopping. 'The view from Colville to Clark’s fork was intercepted by mountain 
ranges, whose tops and sides, covered with snow, presented a barren and cold appearance. 'The 
remarkable similarity and unbroken lines they present, with the exception of the passes, through 
which the principal tributaries flow, taken in connexion with the country between them, enable 
me to take a general view of the entire trip. This narrow belt was level, with a gradual slope 
to the south, covered with timber and generally free from rocks. ‘The soil near the camps sand, 
with some alluvium. ‘he river in its meanderings divides it into alternate prairies from four to 
six miles in length, and one to two miles in width. ‘The river has a rapid current, and is filled with 
innumerable small rapids. The rapid known as the Little Dalles is the only one that would 
impede navigation. A delay of half an hour at the upper extremity to repair canoes, enabled me 
to examine it. The river at this stage of the water had contracted to the width of about twenty 
feet ; the sides solid rock. The current at this time very rapid, and at the highest stage of the 
