The Southern Pacific narrow-gauge system was a network of 3 ft (914 mm) narrow-gauge railroad lines operated by the Southern Pacific Railroad (SP) in the western United States.
It consisted of two lines acquired in the early 20th century, running from western Nevada into eastern California and southern Oregon.
The first, the former Carson and Colorado Railway, comprised 300 miles of single track running south from the Southern Pacific main line between Mound House, Nevada (outside Carson City) and Keeler, California.
It comprised 200 miles of single track running north from Reno, Nevada to Lakeview, Oregon.
The line was converted to standard gauge in 1928, and its 3 ft (914 mm) gauge equipment was sold,[3] though several locomotives subsequently ran on the southern limb of the network, the former Carson and Colorado line.