The San Diego & Arizona Eastern is the HO scale (1/87th actual size) layout of the San Diego Model Railroad Association. HO is the most popular scale in model railroading . The SD&AE models the prototype railroad of the same name connecting San Diego with El Cajon and El Centro. The San Diego - San Ysidro and San Diego - El Cajon portions are now part of the San Diego Trolley. This layout features an impressive 10 ft. high model of the Carriso Gorge (north of Jacumba in eastern San Diego County) and the Goat Canyon trestle. The actual trestle was the largest timber railroad trestle in the world at the time of its construction in 1932.
Because of the rough terrain, the SD&AE has been coined "The Impossible Railroad". The San Diego Model Railroad Association meets every Friday evening.