Donner Summit Railroad Tunnels

After two years of construction, in often abominable conditions, the Central Pacific Railroad sent its first passenger trains through the Summit Tunnel at Donner Pass in November of 1867. The 1,659-foot Summit Tunnel (also known as Tunnel #6) was the most difficult engineering challenge of the Transcontinental Railroad and the engineering marvel of the 19th Century. There were four crews of Chinese laborers working to blast out the tunnel from the granite rock. One crew attacked the rock face at each end, and two crews worked from the center of the tunnel toward each end. These two crews were lowered into the tunnel from a 75 ft. deep vertical shaft excavated down from Donner Pass.

The virtual-reality tour below begins with a satellite view of the entire Donner Summit area.

Click the image above to enter the virtual-reality tour.
Then click and drag to explore the tunnels and snow sheds at Donner Summit. Double-click for full screen.

The railroad was not the first to create a route over Donner Summit. More than 4,000 years ago members of the Martis Culture of Native Americans traversed these mountain passes and documented their presence with the petroglyphs that may still be seen today. These are included in the VR tour.

Before the railroad came through, the Dutch Flat and Donner Lake Wagon Road served as an essential link over the Sierras. Later, the Lincoln Highway (also seen in the VR tour) followed the same route. With the completion of the Transcontinental Railroad in 1869, its 1,912-mile of continuous steel rail provided a tangible symbol of a unified nation emerging from the bloody discord of the Civil War.

In 1925, the Southern Pacific Railroad built a second—longer and deeper—tunnel over Donner Pass. This 10,325 ft. shaft was dubbed “the Big Hole,” although its official name is “Tunnel 41.” Both tunnels were used until 1993 when the railroad mothballed the original route and removed its rails. Today all train traffic through Donner Summit passes through the “Big Hole,” with east-bound passengers exiting the tunnel to views above Donner Lake (as noted in the VR tour), and west-bound trains leaving the tunnel near Norden.

Click here to see the location in Google Maps.

Click on the image below to enter a gallery of 3D images made
during the construction of the railroad through Donner Summit.

Most of the text captions within the VR tour and on the stereocards pages were initially created by railroad historian Wendell Huffman, the co-author of our book on Alfred A. Hart’s 3D photographs of the construction of the Central Pacific Railroad, Waiting for the Cars.
We are grateful for the corrections and suggestions provided by author and historian (and resident of Donner Summit) Bill Oudegeest.