The gentleman of whom I am speaking is an Englishman, by the name of Hamilton, of the most pleasing and entertaining conversation, whose mind seems to be a complete store-house of ancient and modern literature and art; and whose free and familiar acquaintance with the manners and men of his country gives him the stamp of a gentleman, who has had the curiosity to bring the embellishments of the enlightened world, to contrast with the rude and the wild of these remote regions. We three _bons vivants_ form the group about the dinner-table, of which I have before spoken, and crack our jokes and fun over the bottles of Port and Madeira, which I have named; and a considerable part of which, this gentleman has brought with great and precious care from his own country. This post is the general rendezvous of a great number of Indian tribes in these regions, who are continually concentrating here for the purpose of trade; sometimes coming, the whole tribe together, in a mass. There are now here, and encamped about the Fort, a great many, and I am continually at work with my brush; we have around us at this time the Knisteneaux, Crows, Assinneboins and Blackfeet, and in a few days are to have large accessions. The finest specimens of Indians on the Continent are in these regions; and before I leave these parts, I shall make excursions into their respective countries, to their own native fire-sides; and there study their looks and peculiar customs; enabling me to drop you now and then an interesting Letter. The tribes which I shall be enabled to see and study by my visit to this region, are the Ojibbeways, the Assinneboins, Knisteneaux, Blackfeet, Crows, Shiennes, Grosventres, Mandans, and others; of whom and their customs, their history, traditions, costumes, &c., I shall in due season, give you further and minute accounts. LETTER—No. 4. MOUTH OF YELLOW STONE. The several tribes of Indians inhabiting the regions of the Upper Missouri, and of whom I spoke in my last Letter, are undoubtedly the finest looking, best equipped, and most beautifully costumed of any on the Continent. They live in a country well-stocked with buffaloes and wild horses, which furnish them an excellent and easy living; their atmosphere is pure, which produces good health and long life; and they are the most independent and the happiest races of Indians I have met with: they are all entirely in a state of primitive wildness, and consequently are picturesque and handsome, almost beyond description. Nothing in the world, of its kind, can possibly surpass in beauty and grace, some of their games and amusements—their gambols and parades, of which I shall speak and paint hereafter.