Benjamin Louis Eulalie de Bonneville was an American officer in the United States Army, fur trapper, and explorer in the American West. He is noted for his expeditions to the Oregon Country and the Great Basin, and in particular for blazing portions of the Oregon Trail.

The Oregon Trail was a 2,170-mile (3,490 km) east–west, large-wheeled wagon route and emigrant trail in the United States that connected the Missouri River to valleys in Oregon Territory. The eastern part of the Oregon Trail spanned part of what is now the 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 current states of Idaho and Oregon.