Despite periodic forays to the east, the report of Indian Agent Wilson of Fort Bridger in 1849 indicates that the generally recognized area of Shoshone occupancy was substantially unchanged (J. Wilson, 1849, p. 1002):
Their claim of boundary is to the east from the Red Buttes [near Casper, Wyoming], on the North Fork of the Platte, to its head in the Park, De-cay-a-que or Buffalo Bull-pen, in the Rocky Mountains; to the south, across the mountains, over to the Yam pa pa, till it enters Green or Colorado River; and then across to the Back bone or ridge of mts. called the Bear River mountains, running nearly due west towards the Salt Lake, so as to take in most of the Salt Lake, and thence on to the Sinks of Mary's or Humboldt River; thence north to the fisheries on the Snake river, in Oregon and thence south (their northern boundary) to the Red Buttes, including the source of Green River.
Joseph Lane, the Superintendent of Indian Affairs in Oregon territory also wrote in that year that "the Shoshonee or Snake Indians inhabit a section of country west of the Rocky mountains, from the summit of these mountains north along Wind river mountains to Henry's fork...." (Lane, 1857, p. 158).
Continuing reference to the presence of Shoshone east of the Continental Divide is found in reports dating from the 1850's, although the Green River country continued as the central area of Eastern Shoshone occupation. Indian Agent Holeman sought to bring the Shoshone to a treaty conference at Fort Laramie in 1851 and reported (Holeman, 1852, p. 445):
... met the village assembled on Sweet Water, about fifty miles east of the South pass. On the 21st of August I had a talk with them, which resulted in their selecting sixty of their headmen, fully authorized to act for the whole tribe....
In September, 1852, Brigham Young arranged a peace conference between the Ute and Shoshone. The Mormon governor reported (Young, 1852, p. 438):
I then asked the Shoshones how they would like to have us settle upon their lands at Green River. They replied that the land at Green River did not belong to them; that they lived and inhabited in the vicinity of the Wind River chain of mountains and the Sweet River (or Sugar Water, as they called it), but that if we would make a settlement on Green River they would be glad to come to trade with us.
Difficulties soon developed between the Mormons and the Indians on Green River (Holeman, 1858, pp. 159-160). The report of Lieutenant Fleming of Fort Laramie in 1854 suggests that the Shoshone had not relinquished the Green River country to the Mormon colonists, despite Young's claim (H. B. Fleming, 1858, p. 167):
The mountain men have wives and children among the Snake Indians, and therefore claim the right to the Green River country, in virtue of the grant given them by the Indians, to whom the country belongs, as no treaty has yet been made to extinguish their title.
The Morehead narrative in Connelley's edition of the Doniphan expedition notes that some two or three thousand Shoshone were camped on the Green River in the summer of 1857; Chief Washakie was present at this encampment (Connelley, 1907, p. 607). And Alter's biography of James Bridger states that in the winter of 1857-58 "Chief Washakie and two thousand Shoshone tribesmen at the crossing of the Green had no particular difficulty that winter" (Alter, 1925, p. 303). Forney, in June, 1858, wrote of his plans to establish the Shoshone "under Chief Wash-A-Kee" on the tributaries of the Green River (Forney, 1860b, p. 45) and reported that the group was located on that river in May, 1858 (Forney, 1859, p. 564).