forty or fifty miles wide, and sixty or seventy miles long. This information is strengthened by that of the white hunters, who have explored parts of the lake. The Indians represent, that at the extreme west end of this lake, a large river flows out, and runs in a westward direction. General Ashley, when on those waters, at first thought it probable they were the sources of the Multnomah: but the account given by the Indians, supported by the opinion of some men belonging to the Hudson Bay Company, confirms him in the belief, that they are the head-waters of the river represented as the Buenaventura. To the north and north-west from the Grand Lake, the country is represented as abounding in salt. The Indians west of the mountains are remarkably well disposed towards the citizens of the United States; the Eutaws and Flatheads are particularly so, and express a great wish that the Americans should visit them frequently. A large number of lateral ranges project to the south-east, east, and north-east of the main range. Where the Missouri enters the plains, is the most eastern projection; and from where the Jaune leaves the snowy range, there is a lateral range, running more than two hundred miles south-east, which is intersected by the Bighorn river. As these mountains have not yet been explored by the eye of geological science, it is impossible to say any thing respecting their component parts; but, from every thing that we can learn from Pike and Clarke, they seem to be chiefly granitic. No volcanoes have yet been discovered amongst them; but strange unusual noises were heard from the mountains, by the American party, when stationed above the falls of the Missouri. These sounds seemed to come from the north-west. ‘Since our arrival at the falls,’ says the narrative, ‘we have repeatedly heard a strange noise coming from the mountains, a little to the north of west. It is heard at different periods of the day and night: sometimes when the air is perfectly still and unclouded, and consists of one stroke only, or of five or six discharges in quick succession. It is loud, and resembles precisely the sound of a six pounder at the distance of three miles. The Indians had before mentioned this noise like thunder, but we had paid no attention to it. The watermen also of the party say, that the Pawnees and Ricaras give the same account of a similar noise made in the Black Mountains, to the westward of them.’ Again, near the same place, it is afterwards said: ‘They heard, about sunset, two discharges of the tremendous mountain artillery.’ Not a word more occurs upon the subject; but we know that similar explosions take place among the mountains near the head of the Washita, and among the mountains of Namhi, near the sources of the Red river.