Emigrant Gap, Rail mountain pass in Sierra Nevada, California.

Emigrant Gap is a low gap in a ridge of the Sierra Nevada on the California Trail, west of Donner Pass. The surrounding cliffs are so steep that 1840s pioneers had to lower their wagons on ropes to continue. The gap marks the crossing from the American River drainage to the Bear River drainage.

The first documented crossing occurred in 1844 when the Stephens-Townsend-Murphy Expedition traveled through here on their way across the Sierra Nevada. This journey opened the route for settlers who came after them.

The name refers to emigrants on the California Trail who crossed from the American River drainage to the Bear River drainage through this low gap. In the 1840s they had to lower their wagons by ropes down the cliffs to reach Bear Valley. A California Historical Landmark plaque, number 403, dedicated on June 25, 1950, stands along Interstate 80.

The gap sits on Interstate 80 west of Donner Pass, and the California historical marker (No. 403) stands along the highway. Blue Canyon–Nyack Airport nearby has a warm-summer Mediterranean climate with cold, extremely snowy winters, so winter crossings need preparation for snow.

The pass was a critical point on the California Trail where early travelers lowered their wagons using ropes down the steep slopes. This rope method was necessary for many expeditions to cross safely.