Donner Pass Capsule History

Most of the Oakland to Roseville section was constructed by the Central Pacific, some of it as part of the first transcontinental line during the 1860s, and most of it as the “Cal-P” line a little later.  Originally, this included a train ferry crossing of Carquinez Strait between Benicia and Port Costa, west of Martinez. Carquinez Strait was finally bridged, east of Martinez, in 1932.

The line east of Sacramento over Donner Pass was built by the Central Pacific Railroad in the 1860s as part of the first transcontinental railroad. This line started at the east bank of the Sacramento River, at the depot that now forms part of the California State Railroad Museum. Track was laid as far as Roseville by February, 1864, to Rocklin by March, 1864, Cisco by November, 1866, and Reno by June, 1868. The line was joined with the Union Pacific rails coming from the east at Promontory, Utah, in May, 1869.

Originally built as a single track line, the entire route over Donner Pass was doubled as part of the Harriman improvements to the whole Southern Pacific system in the early twentieth century.  Some short segments of the line were singled again in the early 1990s. Once the Western Pacific line was built across Nevada, this and the parallel SP line between Winnemucca and Alazon were operated as a paired track “current of traffic” double track system, an arrangement that persists into the 21st century, when both lines are owned by Union Pacific. The line to the north of the Great Salt Lake was replaced by the trestle/causeway across the lake, touching land at Promontory Point, at the same time. A new causeway replaced this part of the line in the 1950s.

In September, 1996, the entire SP system was merged with Union Pacific, which owns and operates this route.