FROM FORT BENTON TO THE FLATHEAD CAMP. 303 
base, many of them having a perfectly rectangular shape. We crossed, ten miles farther, a fork 
of the Arrow river, now dry, which takes its rise in the Belt mountains. This butte referred to 
rises toa height of about four hundred feet above the valley, and is perfectly flat or level on the 
top; at its edges are seen the outcropping of a dark gray columnar rock encrusted in many places 
with a white salt. The slopes of this butte have an inclination of seventy-five degrees, and are 
covered, as also at the base, with cedar and scrub-pine. The grass of this valley passed through, 
up to noon, we found dry, being buffalo grass; but around the margin of the lakes seen in the 
valley the grass is green, and exceedingly nutritious. The soil is of a light grayish color, as if 
baked in the sun, though covered with grass. There are to be seen along the northern side of 
this valley large beds of rock and salt, alternately. This salt, which I could not examine, but 
was told by Mr. Rose, is a species of Epsom salts, exceedingly purging in its nature, and at a 
distance would appear as so many large masses or beds of snow glistening in the sun. We 
found the valley much cut up with the holes of the badger, one of which the Indians killed. I 
would here mention that these Indians of the Blackfoot nation had betore visited the vicinity of 
the Flathead camp, with the intention, if possible, to steal the horses of the Flatheads; but not 
succeeding, they placed themselves under our protection to visit this camp on friendly terms. 
This instance will show the duplicity to be found at times among the Indians, and especially among 
the Blackfoot nation. Finding they were unable to succeed as enemies, they were willing to try it 
as friends, and they knew they were perfectly safe in visiting the camp of their enemy under the 
protection of the whites. Besides, it is reckoned a coup for them to visit the camp of their 
enemies, a number of which visits makes a man a chief or brave, in the estimation of his people. 
Our guide, who was also a Blackfoot Indian, was acting under a promise. He had engaged to 
conduct us safely to the Flathead camp, to invite the principal men of their nation to accompany 
us across the Rocky mountains to the village of St. Mary’s, and had engaged to conduct us across 
the Rocky mountains by one of the travelled trails, when he was promised to have a letter to 
the gentleman in charge of Fort Benton, stating that he had faithfully performed his duty, when 
he would receive his reward. Had he received it before he had performed his duty, I am con- 
vinced that he would have left me at the end of the first day. 
Unfortunately, this morning I found that the barometer used by Mr. Burr had become unfit for 
service, which I sorely regretted, since I had anticipated having an excellent barometrical profile 
over anew and untravelled route. At noon we halted for one and a half hours, when we 
resumed our journey in the same direction until 4 p. m., when, one of the mules of Mr. Rose 
breaking down, we halted, after twenty-one miles’ march, on the east bank of the main stream of 
the Arrow river, which we found to be a small and tortuous stream, that takes its rise in the 
rocky buttes of the Belt mountains, and empties into the Missouri twenty-five miles below Fort 
Benton. Its banks are well wooded, the cotton-wood tree being the most abundant; the scrub- 
cedar also occurring, though not abundantly. We found on this river good grass and wood ; 
but the water was hard and brackish. 
The river runs in a general direction nearly north through a very beautiful valley that crossed 
at right angles the valley through which we had been journeying all day. The valley is lined 
on each side by high clay bluffs, with occasional out-croppings of a dark-colored rock. Game 
was exceedingly scarce; prairie dogs being the only living thing seen, save occasionally a wolf or 
an antelope, which latter would be frightened from their beds at least a mile in advance of us, and 
soon would be seen bounding off to the mountains that limited our view to the right of the valley. 
Grass we found tobe dry, though highly relished by the animals; the only water seen was the 
fork of Arrow river that takes its rise in the Square Butte of the Belt mountains, and a small 
brook, about two feet wide, that takes its rise from a spring in the bluffs of the valley. We had 
the fork of Arrow river referred to to our right until we struck the main stream. During this 
night we were visited by an exceedingly heavy rain, accompanied by much thunder and light- 
ning, which was concentrated in the western portion of the horizon. It rained from 9 to near 
