freight train coming up Donner Summit, California

Transcontinental Railroad over Donner Pass

Mileages From Sacramento

  • Colfax - 50 miles
  • Yuba Gap - 74 miles
  • Soda Springs - 89 miles
  • Donner Summit - 91 miles
  • Donner Lake - 98 miles
  • Truckee - 101 miles

The Transcontinental Railroad over Donner Pass

The Transcontinental Railroad connecting California with the eastern states was completed in 1869. The most difficult challenge in its construction was the crossing of the Sierra over 7,056-foot Donner Pass. The 1,659-foot-long Summit Tunnel in combination with four other tunnels, miles of snow sheds, and a pair of Chinese Walls proved an engineering and construction challenge for the Central Pacific Railroad.

Today much of the original route surveyed by Chief Engineer Theodore D. Judah is still in use. The Summit Tunnel has been replaced by a 10,322-foot tunnel known as The Big Hole, which passes beneath Mt. Judah about a mile south of Donner Pass. Ownership of the railroad passed to the Southern Pacific Railroad and then in 1996 to the current owner, Union Pacific Railroad.

Today, nearly 150 years after its completion, the transcontinental railroad still attracts a lot of interest. Although some sections of the original route have been improved with new tunnels and realigned tracks, the basic route is till the same as it was back in 1866. Trains still climb the steep mountainsides, fight their way through winter snow, and roll down the long, winding grades.

Building the Transcontinental Railroad over Donner Pass

Cape Horn

In 1865 the Central Pacific Railroad began to push the tracks east from Camp 20 (today's Colfax) along a steep section of the North Fork of the American River Canyon. Trestles crossed several deep gorges. The railroad bed around the Cape Horn peninsula, 1,400 feet above the river, took nearly a year to complete. In 1913 a tunnel was bored through the mountain for a second track.


The first two tunnels, known as the Grizzly Hill Tunnel and the Emigrant Gap Tunnel, were bored west of Cisco in 1866.

transcontinental railroad tunnels, donner summit, CA

The 1,659-foot Summit Tunnel (tunnel #6) took over 15 months to excavate. Most of the workers were Chinese who toiled with hand drills and risked their lives with black powder and newly invented nitroglycerine. A vertical shaft was sunk to allow construction in both directions away from the middle of the tunnel. The tunnel was completed in 1867, nearly a year before the first train would pass over the tracks. The Summit Tunnel was replaced by a longer Mount Judah Tunnel in 1925. The tracks over the highest portion of the line have been removed.

Two shorter tunnels, #7 and #8, were constructed just east of Donner Pass. A long stone embankment, known as the China Wall, was built up to support the railroad bed along this treacherous section of track.

Snow Sheds

Snow sheds--cavernous wooden tunnels--were constructed in many sections along the track were snow drifts or avalanches threatened to close the tracks during the winter. The shed complex near Norden developed into a virtual underground city for railroad workers with homes and even a restaurant all interconnected by wooden tunnels. Today many of the wooden snow sheds have been bypassed by the new tunnel or replaced with concrete and steel sheds.

Where to View the Transcontinental Railroad

Colfax Passenger Depot

The Colfax Passenger Depot was built in 1905 for the Nevada County Narrow Gauge railroad. In more recent years it served as a station for AMTRAK's California Zephyr. Recently renovated, the picturesque building stands adjacent to the tracks in downtown Colfax.

Cape Horn Viewpoints

  1. Historical marker along Highway 174, ½ mile north of Colfax
  2. Stevens Trail, south side of Interstate 80 in Colfax
  3. Norton Grade Road, off Rollins Lake Road, limited parking

Old Highway 40 from Colfax to Baxter

The map below shows numerous places you could park safely and wait for a train to pass. Bring a good book and your camera and set yourself up at one of the crossings or in a place where the tracks parallel the road.

map of the transcontinental railroad from Colfax to Baxter, CA

Nyack - Emigrant Gap

From Nyack take Nyack Road northeast, or from Emigrant Gap take Texas Hill Road southwest.

Soda Springs - Norden

The tracks pass right through Soda Springs, just to the south of the main road. Take the Soda Springs Road turnoff from Donner Pass Road and you will cross the tracks almost immediately. Farther east on Donner Pass Road near Norden you can follow a dirt road down to the edge of the tracks and watch the eastbound trains emerge from the snow sheds.

Truckee railroad station, Truckee, CA

Coldstream Canyon

Trails from Donner Memorial State Park lead out Coldstream Canyon where the tracks make a large horseshoe turn.

Truckee Station

The train station in Truckee (10065 Donner Pass Road) makes a great place to watch the trains come and go. The present station was built in 1900. It shares its space with the Chamber of Commerce and Visitor's Center.