One of the animals that was quite new to the explorers was the elusive mountain goat.
Capt. Lewis, August 24, 1805--The few guns which the Shoshones have are reserved for war almost exclusively and the bow and arrows are used in hunting. I have seen a few skins among these people which have almost every appearance of the common sheep. They inform me that then finde this animal on the high mountains to the West and S. W. of them it is about the size of the common sheep, the wool is reather shorter and more intermixed with long hairs particularly on the upper part of the neck. these skins have been so much woarn that I could not form a just Idea of the animal or it's colour. The Indians however inform me that it is white ant that it's horns are lunated comprest twisted and bent backward as those of a common sheep. The texture of the skin appears to be that of the sheep. I am now perfectly convinced that the sheep as well as the bighorn exist in these mountains. (Capt C saw one at a distance to day)
Capt. Clark, October 29, 1805--I also Saw a mountain Sheap skin the wool of which is long, thick, & corse with long corse hare on the tope of the neck and back something resembling bristles of a goat, the skin was of white hare, those animals these people inform me by signs live in the mountains among the rocks, their horns are Small and streight
Capt. Lewis, February 22, 1806--The sheep is found in various parts of the Rocky mountains, but most commonly in those parts which are timbered and steep. they are also found in greater abundance on the Chain of mountains w[h]ich form the commencement of the woody country on this coast and which pass the Columbia between the great falls and rapids. we have never met with this anamal ourselves but have seen many of their skins in possession of the natives dressed with the wooll on them and a[l]so seen the blankets which they manufacture of the wooll of this sheep. from the skin the animal appears to be about the size of the common sheep; of a white colour. the wooll is fine on most parts of the body but not so long as that of our domestic sheep. the wooll is also curled and thick. on the back and more particularly on the top of the neck the wooll is intermixed with a considerable proportion of long streight hairs. there is no wooll on the small part of the body behind the sholders on each side of the brisquit which is covered with a short fine hairs as in the domestic sheep. form [from] the signs which the Indians make in discribing this animal they have erect pointed horns, tho' one of our Engages La Page, assures us that he saw them in the black hills where the little Missouri passes them and that they were in every rispect like the domestic sheep, and like them the males had lunated horns bent backwards and twisted. I should be much pleased at meeting with this animal, but have had too many proofs to admit a doubt of it's existing and in considerable numbers in the mountains near this coast.
Capt. Lewis, April 10, 1806--on entering one of these lodges, the natives offered us a sheepskin for sail, than which nothing could have bee more acceptable except the animal itself. the skin of the head of the sheep with the horns remaining was cased in such manner as to fit the head of a man by whom it was woarn and highly prized as an ornament. we obtained this cap in exchange for a knife, and were compelled to give to Elkskins in exchange for the skin. this appeared to be the skin of a sheep not fully grown; the horns were about four inches long, celindric, smooth, black, erect and pointed; they rise from the middle of the forehead a little above the eyes. they offered us a second skin of a full grown sheep which was quite as large as that of a common deer. the discovered our anxity to purchase and in order to extort a great price declared that they prized it too much to dispose of it. in expectation of finding some others of a similar kind for sale among the natives of this neighbourhood I would not offer him a greater price than had been given for the other which he refused. these people informed us that these sheep were found in great abundance on the hights and among the clifts of the adjacent mountains. and that they had lately killed these two from a herd of 36, at no great distance from their village.