- a route used during the U.S. westward migrations, especially in the period from 1840 to 1860, starting in Missouri and ending in Oregon. About 2,000 miles (3,200 km) long.
- an early pioneering route across the central US, from Independence, W Missouri, to the Columbia River country of N Oregon: used chiefly between 1804 and 1860. Length: about 3220 km (2000 miles)
