Beginning in 1843, nearly one thousand Americans left Missouri for the Oregon Country, and during the next two decades more than 50,000 emigrants sought new lives in what some called the "Garden of the World." The Oregon Trail was not a single route but a changing network of paths, river passages, cutoffs, and alternate roads stretching more than two thousand miles from the Missouri River toward the Pacific and the Willamette Valley. Early emigrants blazed routes and often traveled by canoe, raft, bateau, or wagon, while later travelers used alternatives such as the route to The Dalles, Barlow's road around Mt. Hood, and steamboats below the Cascades. The journey was arduous, and hardship, privation, illness, and death were constant companions across prairies, mountains, deserts, and rivers. Disease also devastated Native peoples; epidemics in the Willamette Valley and Columbia estuary in 1830-32 destroyed an estimated 75% of the native population, and later waves of emigrants brought further contagion into a region where Native communities had long lived by highly developed hunting, gathering, and trade. Relations between Indians and emigrants included barter and mutual assistance, but the influx of settlers and the taking of 320 acre land claims set the stage for tragedy because tribal relationships to land did not match federal ideas of purchase from a "head chief." The trail drew a diverse population, including people of many ethnic backgrounds and economic circumstances, though outfitting for the journey was expensive. Its history was also preserved in more than 2,000 emigrant journals, which recorded hunger, weather, crowded roads, abandoned possessions, sickness, and relief at reaching Oregon. The movement west grew out of larger forces including the fur trade, the Lewis and Clark expedition, Astoria, international rivalry between Great Britain and the United States, the 1846 settlement of the Oregon boundary at the 49th parallel, economic hardship, and the attraction of free farmland. Between 1830 and 1870, historians estimate that more than 250,000 emigrants used the Oregon Trail and its variants, and during the covered wagon era from 1841 to 1866 approximately 500,000 people traveled westward on the Oregon-California Trails.