Surveyors called the San Diego and Arizona Railway (SD&A) The Impossible Railroad because of its jagged, mountainous, and brutal desert route. The financier and driving force behind building this binational 148-mile rail connection to the east from San Diego, California, was businessman John D. Spreckels. Because of his perseverance, the jinxed 19071919 construction overcame a series of disasters, including the Mexican Revolution, a prolonged lawsuit, floods, World War I, labor shortages, a tunnel cave-in, and a lethal pandemic. Once up and running, the line was intermittently in and out of service and later sold and renamed the San Diego and Arizona Eastern Railway. While The Impossible Railroad still faces constant challenges and partial closures, freight and trolley service currently operate on its right-of-way, and tourist excursions are offered at its Campo, California, depot.

Surveyors called the San Diego and Arizona Railway (SD&A) "The Impossible Railroad" because of its jagged, mountainous, and brutal desert route. The financier and driving force behind building this binational 148-mile rail connection to the east from San Diego, California, was businessman John D. Spreckels. Because of his perseverance, the jinxed 1907-1919 construction overcame a series of disasters, including the Mexican Revolution, a prolonged lawsuit, floods, World War I, labor shortages, a tunnel cave-in, and a lethal pandemic. Once up and running, the line was intermittently in and out of service and later sold and renamed the San Diego and Arizona Eastern Railway. While "The Impossible Railroad" still faces constant challenges and partial closures, freight and trolley service currently operate on its right-of-way, and tourist excursions are offered at its Campo, California, depot.