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 same complete way as did the northern Algonkian and Athapaskan peoples. After the decline of the fur trade, the Shoshone did not return to their pristine state of isolation. In the early 1840's, shortly after the debacle of the beaver trade, a strong surge of immigration from the States to Oregon began. The road to Oregon followed trails well marked by the trappers. It ascended the Platte and North Platte rivers and thence to the South Pass via the Sweetwater. From South Pass the trail went down to Fort Bridger, established in 1843, and then turned to the northwest and Fort Hall on the Snake River. The California branch of the trail bent southwest before reaching Fort Hall and descended the Humboldt River. The initial trickle of emigration grew into a great stream, and after the discovery of gold in California the Oregon Trail became a great highway to the west. Busy though the trail was, the emigrants had but a single purpose. This was to cross the "Great American Desert," or the Plains, and reach the promised lands of the Pacific Coast. Except for the immediate environs of the emigrant road, the mountain country contained fewer whites than during the previous decade. This situation soon changed. In 1847 the Mormon migration reached the Salt Lake Valley, and during the following years Mormons settled adjacent areas of Wyoming and Idaho. Miners poured into the Sweetwater River country of Wyoming in the 1860's and in 1869 Fort Stambaugh was established at South Pass to protect them and the emigrant road. This route, however, had already seen its greatest days, for the Central Pacific Railroad was completed in the same year.