The Oregon Trail, Ruts Across the Snake River Plain

Between eighteen forty-one and eighteen sixty, somewhere between three hundred thousand and five hundred thousand emigrants crossed present-day Idaho on the Oregon Trail. They came from Missouri and Iowa and Ohio, their wagons loaded with furniture they would throw away, food they were rationing by Kansas, and dreams of farmland in the Willamette Valley they had never seen.

The southern Idaho stretch was not their favorite. The trail followed the Snake River for nearly three hundred miles, close enough to see water in the canyon but often too steep to reach it. Temperatures in July and August could top a hundred degrees. The sagebrush plain offered little shade. The oxen weakened. Wagon wheels cracked in the dry heat. Graves appeared with more frequency on the Idaho portion of the trail than almost anywhere else.

A few crossings of the Snake River existed. The Three Island Crossing near present-day Glenns Ferry was the most famous, where emigrants could ford the river at lower summer levels to reach the north bank and slightly better grass. In high water years they stayed on the south bank and took the harder dry route. Either way, they kept walking.

The trail through Idaho passes through terrain that has changed surprisingly little. In the Owyhee county highlands, and near the Massacre Rocks section along the Snake, the wheel ruts of emigrant wagons are still visible, cut four to six inches deep into the volcanic soil. You can walk them. The Oregon Trail National Historic Trail today marks more than two thousand miles from Missouri to Oregon, but some of its most unaltered physical evidence lies right here in southern Idaho, preserved not by any park service boundary but simply by the fact that no one found a reason to plow these particular fields.