The journal of Thomas J. Farnham, written in 1839, documents the growing economic difficulties of the Shoshone of the Wyoming-northern Utah area. In July of that year, Farnham received news that the Shoshone on the Bear River were "starving" and subject to the depredations of marauding Blackfoot and Siouan war parties (Farnham, 1906, p. 229). While on "Little Bear River" (a Bear River tributary), Farnham observed that, despite the present barrenness, he had heard that this area was formerly rich in buffalo and that game had abounded in the mountains (p. 233). Further indication of the growing poverty of the Shoshone country is seen in his comment that the Shoshone suffered less from enemy attacks because "the passes through which they enter the Snake country are becoming more and more destitute of game on which to subsist" (pp. 262-263).

Poverty, it would seem, did not bestow complete immunity upon the Shoshone of Wyoming nor did it entirely inhibit occasional forays against their enemies. Father De Smet, who was present at the Green River rendezvous in 1840, wrote that the "Snakes" were then preparing a war party against the Blackfoot (De Smet, 1906, 27:164). But by 1842, the Shoshone had other concerns than the traditionally hostile Blackfoot. Medorem Crawford noted that on July 23, 1842, the encampment of whites then situated near the Sweetwater River was joined by a party of over one hundred "Sues and Shians who had been to fight the Snakes" (Crawford, 1897, p. 13). The Shoshone had experienced previous armed encounters with Siouan groups to the east, but the pressure of the latter in these years was such that the Crow and Shoshone allied for defense against the powerful eastern tribes (Fremont, 1845, p. 146). The Crow, according to Fremont, had been present at the 1842 rendezvous on Green River (p. 50). Despite the alliance, Fremont regarded the Wind River Mountains as the eastern limit of Shoshone occupancy. He noted in 1843 that the Green River was twenty-five years earlier "familiarly known as the Seeds-ke-dee-agai, or Prairie Hen River; a name which it received from the Crows, to whom its upper waters belong" (p. 129), and both Farnham (1906, p. 261) and Russell (1921, pp. 144-146) placed the Shoshone no farther east than the Green River drainage in the years immediately preceding Fremont's observation.

Siouan aggressions continued over an indefinite period, for Bryant reported in June, 1846, that about 3,000 Sioux had collected at Fort Laramie preparatory to an attack against the Shoshone and Crow (Bryant, 1885, p. 107). Bryant and his companions informed the Shoshone of the impending raid when they arrived at Fort Bridger on July 17, 1846. The approximately 500 Shoshone assembled there broke camp immediately, presumably to organize a defense (pp. 142-143).

During the decade of the 1840's, accounts of the presence of Shoshone beyond the Continental Divide are found with increasing frequency. In 1842 W. T. Hamilton, while on the Little Wind River, noted that the trappers and the Shoshone were in continual jeopardy in this region because of "Blackfeet, Bloods, Piegans and Crows" (Hamilton, 1905, p. 52). Although his party was attacked by a Blackfoot group at this time, they sighted a Shoshone party shortly thereafter (p. 61) which was under the leadership of Chief Washakie (pp. 63-64). Other Shoshone joined this group, claiming that they had fought with Pend Oreille Indians near the Owl Creek Mountains on the north side of the Wind River Valley (p. 69). (The identification of this group may well have been erroneous in view of the northerly locale of the Pend Oreille.) The Shoshone met by Hamilton later gathered at Bull Lake to prepare an attack against the Blackfoot on the Big Wind River (p. 71); twenty "Piegans" were later encountered in the Owl Creek Range (p. 80).

These events apparently transpired in the late spring or early summer of 1842, for summer found Washakie's people at Fort Bridger (p. 92), and later at Brown's Hole on the Green River in northwestern Colorado where a "few Ute and Navajos came up on their annual visit with the Shoshone, to trade and to race horses." The Shoshone left for their fall trapping in September (p. 97), but some were there in winter camp when Hamilton's party returned to Brown's Hole to winter (p. 118).

Hamilton's later travels took him on a buffalo hunt into the Big Horn Basin with Washakie in October, 1843 (p. 182). At "Stinking Water" (Shoshone River) the party encountered Crow Indians on their way to visit the Shoshone (p. 183). The buffalo-hunting group returned to the Green River in November for the winter (p. 186). At this time Hamilton noted that Washakie claimed the Big Horn country as far as the Yellowstone River, but that the Crow, Flathead, and Nez Percé hunted upon it and it was regarded as neutral hunting ground by other tribes (p. 187). October, 1848, again found Hamilton in the Big Horn country, where he met a party of Shoshone in the Big Horn Mountains (p. 197). The group was in pursuit of a Cheyenne war party that had stolen horses from them; the offenders were overtaken on the North Platte River and the horses were recovered (p. 198). Hamilton was informed that Washakie was then on Greybull Creek, but planned to move to the Shoshone River (p. 199).

Further information on the activities of the Shoshone east of the Continental Divide comes from Bryant, who, on July 14, 1846, sighted near Green River (Bryant, 1885, p. 136):

... a party of some sixty or eighty Shoshone or Snake Indians, who were returning from a buffalo hunt to the east of the South Pass. The chief and active hunters of the party were riding good horses. The others, among whom were some women, were mounted generally upon animals that appeared to have been nearly exhausted by fatigue. These, besides carrying their riders, were freighted with dried buffalo meat, suspended in equal divisions of bulk and weight from straps across the back. Several pack animals were loaded entirely with meat and were driven along as we drive pack mules.

The apparent increase in the use of the Wind River Valley and adjacent areas was in part a result of Crow amity in the face of a common enemy, but it can also be explained in terms of the Shoshone need to seek their winter store of buffalo meat regardless of dangers. The buffalo herds west of the Continental Divide were greatly diminished by 1840, and, by the end of the decade, the intrusion of emigrants must have decimated the remaining stock. As early as 1842, Fremont commented that he saw no buffalo beyond South Pass (Fremont, 1845, p. 63), and in 1849 Major Osborne Cross observed that "scarcely any were to be met with this side of the South Pass" (Cross, 1851, p. 178). The Major later wrote (p. 182):

Game in this section of the country is scarce, compared with the ranges passed over on the route. We had now gone nearly through the whole buffalo range, as but few are now met with on Bear River. Fifteen years ago they were to be seen in great numbers here, but have been diminishing greatly since that time.