More crushed gypsum heads to Plaster City (where it will be crushed even more). The mine railroad was originally conceived and built by a San Diego pharmacist, Samuel Dunnaway, who had relocated to El Centro and became aware of a vast deposit of gypsum in the Fish Creek Mountains. Dunnaway formed the Imperial Gypsum & Oil Company in 1920 and began construction of a 3-foot gauge railroad from the mine to a connection with the San Diego & Arizona Eastern in what would eventually become Plaster City. Construction (and later operation) was challenged by drifting sand, as well as sand’s lack of resilience to flooding, but there were no major issues and the line was built as scheduled. One-hundred-and-four years later, the narrow gauge trains keep on coming.