The railroad industry enjoys a long and fascinating history in the San Diego, California area. San Diego rail history dates back to 1886, when the San Diego and Cuyamaca railroad was established to service the Southern California land boom. Some of the important early rail companies were the San Diego, Cuyamaca & Eastern railway connecting San Diego to points east, the San Diego & Arizona railway through the stunning Carriso Gorge, and the San Diego Southern railway leading to the south. The San Diego & Arizona provided passenger and freight service through both World Wars I and II but is strictly a freight line today.

The Southern and Cuyamaca rail lines merged in 1912. By the fifties, the volume of railroad freight service on this line had grown so large that it was too heavy for the railroad to handle. Service had to be scaled back to three times a week . Even the thrice-weekly traffic strained the line by the sixties. A solution was implemented in 1961 when a mile-long extension to the warehouse district of Cuyamaca , which included the large Montgomery Ward warehouse, was built.

Many organizations exist today to preserve the story of San Diego rail. The Pacific Southwest Railway Museum, located in Campo, strives to preserve many of the trains of decades past. The San Diego Electric Railway Association is preserving the electric rail cars that served the streets of the city. Other railroad preservation organizations include the National Trust for Historic Preservation and the Association of Railway Museums.

Through the hard work of the rail enthusiasts of San Diego, more than a century of rail history in Southern California has been preserved. The colorful story of San Diego railroads will be an attraction for visitors to the area to enjoy for years to come.