Bureau of Land Management, Idaho.
The Oregon Trail Scenic Byway follows the main Oregon Trail from the crossing of the Snake River near Glenns Ferry to Bonneville Point, southeast of Boise. Part 1 of the byway is a loop drive that takes you to the south side of the Snake River to view the Three Island Crossing location from the bluffs above the river, then ends on the north side of the river at Three Island Crossing State Park interpretive center. Parts 2 and 3 take county roads to follow the Oregon Trail from Glenns Ferry to Bonneville Point. Oregon Trail ruts are visible along much of this route. Several locations allow access for hiking and horseback riding on the Oregon Trail. The main Oregon Trail from Three Island Crossing to Boise was the primary route utilized by the emigrants for the first 10 years of the trail. Those emigrants who could not cross the Snake River were forced to follow the south side of the Snake River on a route known as the South Alternate. Freight and stage roads to the railroad in northern Utah utilized much of the Oregon Trail for many years. The Oregon Trail continued to be used long after the building of the railroads across southern Idaho, even into the early 1900s. The total distance of the byway is 89 miles. Allow eight hours to complete the trip from Boise, including time to visit the Three Island Crossing State Park interpretive center and to explore the Oregon Trail at the various access points along the way. All of the byway roads are paved or good gravel roads. High clearance vehicles may be required to access the trail off the byway. Four-wheel drive is not needed for the byway, but please stay off the access roads if they are wet or muddy.
Learn more: http://www.nps.gov/oreg/planyourvisit/directions.htm.