Union Pacific in Afton Canyon, Mojave Desert, California

Some historical background that may be of interest: This is the original route of the Los Angeles & Salt Lake Railroad, built in 1905, between those cities. Las Vegas, Nevada, owes its existence as a city to this construction; in 1905, lots were platted and sold along the railroad line at what's now the intersection of Fremont and Main streets. Las Vegas now counts this as its founding, and even had a centennial celebration in 2005. Previously Las Vegas ("The Meadows" in Spanish, due to a large spring) had only been a stop on the Old Spanish Trail and counted only a handful of inhabitants at a couple of ranches. The railroad located a station there because of the spring, which furnished water for the locomotives. So, Las Vegas began its existence as a little railroad town! It remained so until the 1930s, when the construction of Hoover (Boulder) Dam on the Colorado River started its explosive growth in the 20th century.
The Mojave River flows thru Afton Canyon, and usually has surface water here because the shallow bedrock forces it to the surface. It's thus an unexpected oasis in the desert. The Mojave rises in the San Bernadino Mountains on the eastern margin of the Los Angeles basin.