the current of the Missouri is gentle, and two hundred and twenty-two yards in width, the bed principally of mud (the little sand remaining being wholly confined to the points) and still too deep to use the setting pole.  If this be, as we suppose, the Muscleshell, 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 their giving a similar account of the timber where we now are, that the timber of which they speak is similar to that which we have seen for a few days past, which consists of nothing more than a few straggling small pine and dwarf cedar, on the summits of the hills, nine-tenths of the ground being totally destitute of wood, and covered with a short grass, aromatic herbs, and an immense quantity of prickly pears:  though the party who explored it for eight miles represented low grounds on the river as well supplied with cottonwood of a tolerable size, and of an excellent soil.  They 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 Birdwoman’s river, discharges itself into the Muscleshell 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 only 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 much accustomed to it, the taste is not perceptible.  Among the game to-day 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 colours are brighter than those common in the United States.

Tuesday 21.  The morning being very fine we were able to employ the rope and made twenty miles to our camp on the north.  The shores of the river are abrupt, bold and composed of a black and yellow clay, the bars being formed of black mud, and a small proportion of fine sand; the current strong.  In its course the Missouri makes a sudden and extensive bend towards the south, to receive the waters of the Muscleshell.  The neck of land thus formed, though itself high is lower than the surrounding country, and makes a waving valley extending for a great distance to the northward, with a fertile soil which, though without wood, produces