however, that there has been considerable contention among historians, not only over the route of the de la Vérendrye brothers, but over the identification of the Gens du Serpent. L. J. Burpee has reviewed (1927, pp. 13-23) various conflicting interpretations of the journals, and the matter can hardly be considered settled.

By this period, the Blackfoot and other northern tribes were already armed with guns (see Ewers, 1955, p. 16; Haines, 1938, p. 435), obtained through commerce with the French and English traders of Canada. They had also become mounted, and it may be surmised that the Shoshone lost their equestrian advantage at almost the same time that their enemies acquired guns. Thus the Shoshone retreat from the Canadian plains may well have begun before 1750, as Thompson's narrative indeed suggests (Tyrrell, 1916, pp. 334 ff.). The process was certainly complete by 1805, when Lewis and Clark found the Lemhi River Shoshone hiding in the fastnesses west of the Bitterroot Range and lamenting their loss of the Missouri River buffalo country to better-armed groups. The Shoshone, once masters of the northern Plains, had fallen upon bad times. They complained to the explorers that they were forced to reside on the waters of the Columbia River from the middle of May to the first of September for fear of the Blackfoot, who had driven them out of the buffalo country with firearms (Lewis and Clark, 1904-06, 2:373). Their forays into the Missouri drainage were made only in strength with other Shoshone and their Flathead allies (2:374). The Shoshone apparently were able to utilize areas of Montana adjacent to the Bitterroot Range, for signs of their root-digging activities were seen on the Beaverhead River (2:329-334). This pattern of transmontane buffalo hunting described by Lewis and Clark remained essentially the same until its final end after the establishment of the reservation, and will be described in detail later in this work.

It is possible now to discern three periods in this early phase of Shoshone history. The first, the footgoing period, is unknown, and little can be inferred of Shoshone location and movements. The second period is characterized by the acquisition of the horse, and we would conjecture that a good deal of territorial expansion took place after that time. The Comanche differentiated from the main Shoshone group at the beginning of the eighteenth century. Although the Comanche maintained communication with their northern colinguists, the territories of the two groups were not contiguous by the end of the century, and their histories followed separate courses. The extension of the Shoshone into the northern Plains may possibly have predated the acquisition of the horse, for it seems quite likely that they occupied fairly extensive areas east of the Rockies in the footgoing period. But, on the other hand, it seems unlikely that in the period immediately preceding 1700, the most probable date for the acquisition of the horse, they extended from the Arkansas River on the south to the Bow River in Saskatchewan. This would be especially unlikely if later distribution of Shoshone-speakers in the Basin-Plateau was substantially the same in the earlier period also. We would conjecture, then, that equestrian life gave the Shoshone the mobility to extend into the Canadian buffalo grounds but that they were pushed back beyond the divide well before 1800. As Shimkin has noted, the ravages of smallpox and the resulting decline of population probably contributed to their territorial shrinkage (Shimkin, 1939, p. 22).

By 1810, the early explorations of Thompson, Lewis and Clark, and others bore fruit in the commercial exploitation of the far Northwest. The fur trade had already reached the Plains and the Rockies in Canada, and a fierce competition was being waged by the Hudson's Bay Fur Company and the North West Company for the patronage of the Indians there. The British interests pushed southward from Canada, and in 1809 David Thompson established North West Company trading posts on Pend Oreille Lake at the mouth of the Clark Fork River and another farther up that stream within the borders of present-day Montana. At the same time, American traders were pushing westward, and Andrew Henry crossed the Continental Divide to locate his trading post on Henry's Fork of the Snake River in 1810. Also, John Jacob Astor's Pacific Fur Company established the ill-fated Astoria post at the mouth of the Columbia River in 1811. Although this particular American enterprise foundered, Manuel Lisa, the guiding spirit of the Missouri Fur Company, penetrated the Missouri River country and founded a post on the Yellowstone River at the mouth of the Big Horn in 1807. From this point his trappers spread into the near-by mountain country. The most famous of these mountain men was John Colter, who trapped the country of the Blackfoot and Crow and discovered Yellowstone Park.

The northern Plains and Rockies had thus been entered and partially explored by 1812, and increasing numbers of trappers poured into the new Louisiana Purchase and the lands beyond. Astor stepped into the territory of the Missouri Fur Company after Lisa's death in 1820, and in 1822 the Western Division of his American Fur Company was established. Fort Union was built on the upper Missouri to serve as the headquarters of Astor's mountain realm, and steamboats served the post after 1832. A decade before this date, the Rocky Mountain Fur Company was established, and in the following year, 1823, the company's trappers began to exploit intensively the drainages of the Wind River and the upper Snake and Green rivers. The Rocky Mountain Company established a new pattern of trading. Eschewing the rigid and hierarchical organization of the British companies, it relied mainly upon the services of free trappers, who gathered once a year at agreed places to meet the company's supply trains. These gatherings, the famous trappers' rendezvous, were held in the summer at various places in Shoshone country—Pierre's Hole, Cache Valley, or the Green River.

The trappers of the Rocky Mountain Company and later of the American Fur Company invested every fastness of the Shoshone hunting grounds in relentless pursuit of the beaver, the vital ingredient of the gentleman's top hat. The intense traffic in the Shoshone region was abetted by the penetration of the Snake River drainage by Donald McKenzie of the North West Company, beginning in 1818, and later by Peter Skene Ogden, under the auspices of the Hudson's Bay Company. The climax of fur trapping came in the middle of the decade of the 1830's, for at the peak of activity the commerce collapsed. Competition between the various trading companies had been ruinous, the streams had been thoroughly trapped out, and the beaver hat went out of fashion. By 1840, the fur trade in the northwest part of the United States was substantially ended.

During the period 1810-1840 the Shoshone and their neighbors lost the isolation they had formerly enjoyed and came into close contact with the whites. The latter were of a different type than those with whom the Indians later had to deal. They lived off the land, but at the same time they did not dispossess the Indians from their hunting grounds. Although there were sporadic clashes between the trappers and Shoshone and Bannock groups, relations were largely amicable. The trappers married Indian women and lived for varying periods with Indian bands. And both found a common enemy in the Blackfoot. The Indians also traded with the whites and through them obtained firearms, iron utensils, and other commodities, including the raw liquor of the frontier. But the American companies apparently did not attempt to utilize Indian labor to the same extent as did the British companies. The bulk of the fur yield was garnered by the free trappers and not by Indians. The Shoshone traded some small animal furs and buffalo robes to the whites, but they also sold meat, horses, and other commodities. They never became fur trappers in the