The Utah Southern Railroad was built by the Mormons in 1871-2 to connect Salt Lake City to points south. The line was acquired by the Union Pacific Railroad in 1875. The Utah Southern Railroad name was initially kept as a separate division of the UP, but over time the line was moved around and divided among different UP subsidiaries. A significant portion of the line, from Provo to Lynndyl, is today known as the Sharp Subdivision. A non-contiguous portion of the line through the Salt Lake Valley is today owned by the Utah Transit Authority and used for the TRAXlight rail system.
History
The first portion of the line was constructed between Salt Lake City and York, and acquired by the Union Pacific Railroad in 1875. Under UP ownership, extensions to the line reached as far south and west as Frisco. In 1881 the railroad was merged into the Utah Central Railway, another UP subsidiary. In 1889 that subsidiary was merged into the Oregon Short Line and Utah Northern Railway, another UP subsidiary. The line was transferred and divided during construction of the Los Angeles and Salt Lake Railroad, then partially owned and later fully owned by the Union Pacific. The portion of the former Utah Southern from Lynndyl to Milford was used for the LA&SL main, and remains in use as the primary Southern California - Utah rail trunk today, today known as the Lynndyl Subdivision. The remainder of the former Utah Southern became spurs from the LA&SL main. The spurs to Eureka and Frisco were eventually abandoned. The LA&SL and Utah Southern used different routes between Lynndyl and Salt Lake, resulting in duplicate tracks between those two cities. The Utah Southern built tracks were routed to Salt Lake via Leamington Canyon of the Sevier River, passing through Nephi, Santaquin and Provo; the newer LA&SL built tracks were routed farther west in the desert, via Tooele and around the north end of the Oquirrh Mountains. Over time the tracks via Tooele became the preferred route for through traffic and the tracks via Provo became the secondary or local route. The route via Provo is no longer contiguous. The portion between Provo and Lynndyl is still part of the Union Pacific, and is known as the Sharp Subdivision; the portion through the Salt Lake Valley is no longer contiguous with the rest of the line, nor part of the Union Pacific network. Between Salt Lake City and Provo the former Utah Southern line ran roughly parallel to the Denver and Rio Grande Western's Utah Division. Between these cities, the former Utah Southern route became mostly unused for through traffic after the two companies began sharing track in the 1980s. This portion was later abandoned and the right of way sold to the Utah Transit Authority. The portion of the UTA owned right of way that has been rebuilt provides the corridor for a significant part of the TRAX light rail system, forming almost the entirety of the corridor of the Blue Line. Freight traffic on this portion is now managed by the Salt Lake City Southern Railroad.
