<Tr> <Th> Governing body </Th> <Td> National Park Service </Td> </Tr> <Tr> <Th> Website </Th> <Td> Oregon National Historic Trail </Td> </Tr> <P> The Oregon Trail is a 2,170 - mile (3,490 km) historic East--West, large - wheeled wagon route and emigrant trail in the United States that connected the Missouri River to valleys in Oregon . The eastern part of the Oregon Trail spanned part of the future state of Kansas, and nearly all of what are now the states of Nebraska and Wyoming . The western half of the trail spanned most of the future states of Idaho and Oregon . </P> <P> The Oregon Trail was laid by fur traders and traders from about 1811 to 1840, and was only passable on foot or by horseback . By 1836, when the first migrant wagon train was organized in Independence, Missouri, a wagon trail had been cleared to Fort Hall, Idaho . Wagon trails were cleared increasingly farther west, and eventually reached all the way to the Willamette Valley in Oregon, at which point what came to be called the Oregon Trail was complete, even as almost annual improvements were made in the form of bridges, cutoffs, ferries, and roads, which made the trip faster and safer . From various starting points in Iowa, Missouri, or Nebraska Territory, the routes converged along the lower Platte River Valley near Fort Kearny, Nebraska Territory and led to rich farmlands west of the Rocky Mountains . </P>

What was the main route that settlers took to oregon
find me the text answering this question