The queer rat discovered by Lewis and Clark was then unknown to science. It is now known in the Far West as the pack-rat. It lives in holes and crevices of the rocks, and it subsists on the shells and seeds of the prickly pear, which is usually abundant in the hunting grounds of the little animal. The explorers were now constantly in full view of the Rocky Mountain, on which, however, their present title had not then been conferred. Under date of July 2, the journal says:--

"The mosquitoes are uncommonly troublesome. The wind was again high from the southwest. These winds are in fact always the coldest and most violent which we experience, and the hypothesis which we have formed on that subject is, that the air, coming in contact with the Snowy Mountains, immediately becomes chilled and condensed, and being thus rendered heavier than the air below, it descends into the rarefied air below, or into the vacuum formed by the constant action of the sun on the open unsheltered plains. The clouds rise suddenly near these mountains, and distribute their contents partially over the neighboring plains. The same cloud will discharge hail alone in one part, hail and rain in another, and rain only in a third, all within the space of a few miles; while at the same time there is snow falling on the mountains to the southeast of us. There is at present no snow on those mountains; that which covered them on our arrival, as well as that which has since fallen, having disappeared. The mountains to the north and northwest of us are still entirely covered with snow; indeed, there has been no perceptible diminution of it since we first saw them, which induces a belief either that the clouds prevailing at this season do not reach their summits or that they deposit their snow only. They glisten with great beauty when the sun shines on them in a particular direction, and most probably from this glittering appearance have derived the name of the Shining Mountains."

A mysterious noise, heard by the party, here engaged their attention, as it did years afterwards the attention of other explorers. The journal says:--

"Since our arrival at the falls we have repeatedly heard a strange noise coming from the mountains in a direction 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 without a cloud), 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-pound piece of ordnance at the distance of three miles. The Minnetarees frequently mentioned this noise, like thunder, which they said the mountains made; but we had paid no attention to it, believing it to have been some superstition, or perhaps a falsehood. The watermen also of the party say that the Pawnees and Ricaras give the same account of a noise heard in the Black Mountains to the westward of them. The solution of the mystery given by the philosophy of the watermen is, that it is occasioned by the bursting of the rich mines of silver confined within the bosom of the mountains."

Of these strange noises there are many explanations, the most plausible being that they are caused by the explosion of the species of stone known as the geode, fragments of which are frequently found among the mountains. The geode has a hollow cell within, lined with beautiful crystals of many colors.

Independence Day, 1805, was celebrated with becoming patriotism and cheerfulness by these far-wandering adventurers. Their record says:--

"An elk and a beaver are all that were killed to-day; the buffalo seem to have withdrawn from our neighborhood, though several of the men, who went to-day to visit the falls for the first time, mention that they are still abundant at that place. We contrived, however, to spread not a very sumptuous but a comfortable table in honor of the day, and in the evening gave the men a drink of spirits, which was the last of our stock. Some of them appeared sensible to the effects of even so small a quantity; and as is usual among them on all festivals, the fiddle was produced and a dance begun, which lasted till nine o'clock, when it was interrupted by a heavy shower of rain. They continued their merriment, however, till a late hour."

Their bill-of-fare, according to Captain Lewis, was bacon, beans, suet dumplings, and buffalo meat, which, he says, "gave them no just cause to covet the sumptuous feasts of our countrymen on this day." More than a year passed before they again saw and tasted spirits.