San Diego and Arizona Eastern Railway
The San Diego and Arizona Eastern Railway Company is a short-line American railroad founded in 1906 as the San Diego and Arizona Railway (SD&A) by sugar magnate, developer, and entrepreneur John D. Spreckels. Dubbed "The Impossible Railroad" by many engineers of its day due to the immense logistical challenges involved, the line was established in part to provide San Diego with a direct rail link to the east by connecting with the Southern Pacific Railroad lines in El Centro, California. The SD&A's route originates in San Diego, California, and terminates in El  Centro, California. The SD&AE uses about of the original SD&A system, broken into four segments: SD&AE took over the SD&A's operations in 1933 after financial troubles led Spreckels' descendants to sell their interests in the railroad to the Southern Pacific. Through the years, natural disasters and vandalism rendered sections of the line unserviceable, and portions of the line have been sold to various interests. In 1979, the San Diego Metropolitan Transit System (MTS) bought the SD&AE from Southern Pacific to establish the San Diego Trolley, an intra-county light rail passenger line. The remaining track into Imperial County is  available for freight service, as part of the sale condition to MTS by Southern Pacific. As of 2021, the San Diego and Imperial Valley Railroad has exclusive trackage rights on the SD&AE Main Line and La Mesa Branch to move railcars from the end of the BNSF Railway in Downtown San Diego to industrial customers in the San Diego area and the Mexico–United States border at San Ysidro.