http://en.wikipedia.org/wiki/Donner_PassDonner Pass (el. 7,085 ft (2,160 m)) is a mountain pass in the northern Sierra Nevada, located above Donner Lake about nine miles (14 km) west of Truckee, California. It has a steep approach from the east and a gradual approach from the west.
To reach California from the East, pioneer emigrants had to get their wagons over the Sierra. In 1844, the Stephens-Townsend-Murphy Party followed the Truckee River up into the mountains. At the head of what is now called Donner Lake, they found a low notch in the mountains and became the first overland emigrants to use the pass.
The pass received its name, however, from another group of California-bound emigrants. In early November 1846, the Donner Party found the route blocked by snow and was forced to spend the winter on the eastern side of the mountains. Of the 81 emigrants, only 45 survived to reach California; some of them are alleged to have resorted to cannibalism to survive.
On January 13, 1852, another group became stranded about seventeen miles (27 km) west of Donner pass at Yuba Pass on Track #1 adjacent to Tunnel 35 (on Track #2) at about MP 176.5. Southern Pacific's passenger train City of San Francisco was en route westbound through the gap when a raging blizzard slowed the train to a halt. The passengers and crew were stranded for three days until the nearby highway could be plowed enough for a caravan of automobiles to carry them the few miles to Nyack Lodge.
The pass has been used by numerous transcontinental transportation arteries, including the California Trail, First Transcontinental Railroad, Overland Route, Lincoln Highway, U.S. Route 40 and indirectly by Interstate 80. The pass is a prominent feature along the California Zephyr passenger train.