Oregon Trail Overland pioneer route to the northwestern United States. About 3200 km, about 2000 mi long, the trail extended from Independence, Missouri, to the Columbia River in Oregon. Part of the route followed the Platte River for 870 km (540 mi) through what is now Nebraska to Fort Laramie in present-day Wyoming. The trail continued along the North Platte and Sweetwater rivers to South Pass in the Wind River Range of the Rocky Mountains. From there the main trail went south to Fort Bridger, Wyoming, before turning into the Bear River valley and north to Fort Hall in present-day Idaho. In Idaho the Oregon Trail followed the Snake River to the Salmon Falls and then went