The Tonopah and Tidewater Railroad (reporting mark T&T) was a former class II railroad that served eastern California and southwestern Nevada. The railroad was built mainly to haul borax from Francis Marion Smith's Pacific Coast Borax Company mines located just east of Death Valley, but it also hauled lead, clay, feldspar, passengers and general goods across the desert to a connection with the Atchison, Topeka and Santa Fe Railroad at Ludlow, California, and to the Los Angeles and Salt Lake Railroad (later Union Pacific Railroad) at Crucero, California.