ern, or Oregon, Trail follows the general course of the Missouri to its headwaters, crosses the divide, and proceeds down the Columbia to its mouth; and this marks the general line of Salishan occupancy, which extends northward to the more difficult access opened by the Fraser River. The Salishan tribes form a division, at once separating and transitionally uniting a northern and a southern coastal culture of markedly distinct type. Indeed, the Salish form a kind of key to the continent, touching the Plains civilization to the east and that of the Plateau to the south, as well as the two coastal types; so that there is perhaps no group of Indians more difficult to classify with respect to cultural relationships.
The linguistic diversity of the southern of the two Coast groups bounded by the Salish is far greater than that of the northern. In California alone over twenty distinct linguistic stocks have been noted, and Oregon adds several to this score. Such a medley of tongues is found nowhere else in the world save in the Caucasus or the Himalaya mountains — regions where sharply divided valleys and mountain fastnesses have afforded secure retreat for the weaker tribes of men, at the same time holding them in sedentary isolation. Similar conditions prevail in California, the chequer of mountain and valley fostering diversity. Furthermore, the nature of the littoral contributed to a like end. The North-Western coast, from Puget Sound to Alaska, is fringed by an uninterrupted archipelago; the tribes of this region are the most expert in maritime arts of all American aborigines; and the linguistic stocks, owing to this ready communication, are relatively few. From the mouth of the Columbia to the Santa Barbara Islands, on the contrary, the coast is broken by only one spacious harbour — the bay of San Francisco — and little encouragement is offered to seafarers. Among the tribes of this coast the art of navigation was little known : the Chinook, on the Columbia, and the Chumashan Indians, who occupied the Santa Barbara Islands, built excellent canoes, and used them with
