Those starting from Independence followed the same route as the Santa Fe Trail for some 40 mi (64 km), then turned NW to the Platte and generally followed that river to the junction of the North Platte and the South Platte. Crossing the South Platte, the main trail followed the North Platte to Fort Laramie, while the Overland Trail followed the South Platte. The main trail continued from Fort Laramie to the present Casper, Wyo., and through the mountains by the South Pass to the basin of the Colorado River. The travelers then went SW; the Overland Trail rejoined the route E of Fort Bridger. From Fort Bridger the Mormon Trail continued SW to the Great Salt Lake, while the Oregon Trail went northwest across a divide to Fort Hall, on the Snake River. It then went along the Snake River. The California Trail branched off to the southwest, but the Oregon Trail continued to Fort Boise. From that point the travelers had to make the hard climb over the Blue Mts. Once those were crossed, paths diverged somewhat; many went to Fort Walla Walla before proceeding down the south bank of the Columbia River, traversing the Columbia's gorge where it passes through the Cascade Mts. to the Willamette Valley, where the early settlement centered. The end of the trail shifted as settlement spread.
The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved.