Monday, May 20th, 1805
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 yeaterday; at the distance of two and quater 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 troublsome, 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 Mussleshell River, empties into the Missouri two thousand two hundred and seventy miles above the mouth of the latter river. It is 110 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 appearence 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 the current of the Missouri is gentle, and 220 yards in width, the bed pricipally of mud and still to deep to use the setting-pole. If this be, as we suppose, the Musselshell, our Indian information is, that it rises in the first chain of the Rocky Mountains not far from the sources of the Yellowstone, whence in its course to this place it waters a high broken country, well timbered particularly on its borders, and interspersed with handsome fertile plains and meadows. We have reason, however, to believe, from them giving a similar account of the timber where we are now, that the timber of which they speak is similer to that which we have seen for a few days past, which consists of nothing more than a few straggling small pine and dwarf ceder, on the summits of the hills. The also reported that the country is broken and irregular like that near our camp; that about five miles up a handsome river about fifty yards wide, which we named after Chaboneau’s wife, Sahcajahweah, or Birdwomen’s river, discharges itself into the Musselshell on the north or upper side. Another party found at the foot of the southern hills, about four miles from the Missouri, a fine bold spring, which in this country is so rare that since we left the Mandans we have found one of a similar kind, and that was under the bluffs on the south side of the Missouri, at some distance from it, and about five miles below the Yellowstone; with this exception all the small fountains of which we have met a number are impregnated with the salts which are so abundant here, and with which the Missouri is itself most probably tainted, though to us who have been so mush accustomed to it, the taste is not perceptible. Among the game today we observed two large owls, with remarkably long feathers resembling ears on the sides of the head, which we presume are the hooting owls, though they are larger and their colors are brighter than those common in the United States.