Las Vegas and Tonopah Railroad
The Las Vegas and Tonopah Railroad was a 197.9-mile (318.5 km) railroad built by William A. Clark that ran northwest from a connection with the mainline of the San Pedro, Los Angeles, and Salt Lake Railroad at Las Vegas, Nevada to the gold mines at Goldfield. The SPLA&SL railroad later became part of the Union Pacific Railroad and serves as their mainline between Los Angeles and Salt Lake City.
Source: Wikipedia — Las Vegas and Tonopah Railroad (CC BY-SA 4.0)