Sunday 19.  The last night was disagreeably cold; and in the morning there was a very heavy fog which obscured the river so much as to prevent our seeing the way.  This is the first fog of any degree of thickness which we have experienced:  there was also last evening a fall of dew, the second which we have seen since entering this extensive open country.  About eight o’clock the fog dispersed, and we proceeded with the aid of the towline:  the island near which we were encamped, was three quarters of a mile in length.  The country resembles that of yesterday, high hills closely bordering the river.  In the afternoon the river became crooked, and contained more sawyers or floating timber than we have seen in the same space since leaving the Platte.  Our game consisted of deer, beaver, and elk:  we also killed a brown bear, who, although shot through the heart, ran at his usual pace nearly a quarter of a mile before he fell.  At twenty-one miles is a willow island half a mile in length, on the north side, a quarter of a mile beyond which is a shoal of rapid water under a bluff:  the water continued very strong for some distance beyond it:  at half a mile we came to a sandbar on the north, from which to our place of encampment was another half mile, making in all twenty-two and a quarter miles.  The saline substances which we have mentioned continue to appear; and the men are much afflicted with sore eyes and imposthumes.

Monday 20.  As usual we set out early, and the banks being convenient for that purpose, we used the towline:  the river is narrow and crooked, the water rapid, and the country much like that of yesterday:  at the distance of two and a quarter miles we passed a large creek with but little water, to which we gave the name of Blowingfly creek, from the quantity of those insects found in its neighbourhood.  They are extremely troublesome, infesting our meat whilst cooking and at our meals.  After making seven miles we reached by eleven o’clock the mouth of a large river on the south, and encamped for the day at the upper point of its junction with the Missouri.  This stream which we suppose to be that called by the Minnetarees the Muscleshell river, empties into the Missouri two thousand two hundred and seventy miles above the mouth of the latter river, and in latitude 47 degrees 0’ 24” 6 north.  It is one hundred and ten yards wide, and contains more water than streams of that size usually do in this country; its current is by no means rapid, and there is every appearance of its being susceptible of navigation by canoes for a considerable distance:  its bed is chiefly formed of coarse sand and gravel, with an occasional mixture of black mud; the banks abrupt and nearly twelve feet high, so that they are secure from being overflowed:  the water is of a greenish yellow cast and much more transparent than that of the Missouri, which itself, though clearer than below, still retains its whitish hue and a portion of its sediment.  Opposite to the point of junction