I have heard many places being referred to as being "in the middle of nowhere". The picture of the canyon on the front of this post card looks like it could easily join the "middle of nowhere" group of locations. Fortunately, the caption on the post card saves the day.
The Rainbow Canyon Scenic Drive is a relaxing and enjoyable ride on a paved road through Rainbow Canyon, a deep canyon located just south of the town of Caliente, Nevada on State Highway 317. Rainbow Canyon lies between the Delamar Mountains to the west and the Clover Mountains to the east. The canyon is quite deep and steep, with the canyon lying three thousand feet below the higher peaks of the mountains. Yet what makes Rainbow Canyon an enjoyable drive isn’t tall mountains, but instead the colored rock and interesting rock formations along the road. Throughout the drive, the traveler will see large formations of red rock and rock formations that defy easy description. Additionally, and in contrast to the surrounding mountains, the traveler will come across many cottonwood trees. The reason for all the cottonwood trees is because the drive follows a wash, called the Meadow Valley Wash, for its entire length. This wash usually has no more than a trickle of water in it, but collects enough water during heavy rain events to allow cottonwood trees to grow along its banks. The Rainbow Canyon Scenic Drive closely follows the main line of the Union Pacific Railroad for its entire length. This stretch of the Union Pacific is extremely busy, sometimes averaging one train every twenty minutes or so. There are also numerous railroad tunnels and deep cuts along the railroad, providing the rail fan with excellent train watching and photography.
The railroad referred to on the front of the post card is the Los Angeles and Salt Lake Railroad. Wikipedia provides this information: Reporting mark SLR the Los Angeles and Salt Lake Railroad was a rail company that completed and operated a railway line between its namesake cities, via Las Vegas, Nevada. Incorporated in Utah in 1901 as the San Pedro, Los Angeles and Salt Lake Railroad, the line was largely the brainchild of William Andrews Clark, a Montana mining baron and United States Senator. Clark enlisted the help of Utah's U.S. Senator Thomas Kearns, mining magnate and newspaper man, to ensure the success of the line through Utah. Construction of the railroad's main line was completed in 1905. Company shareholders adopted the LA&SL name in 1916. The railway was also known by its official nickname, "The Salt Lake Route".
The railroad had a run in with the Union Pacific Railroad early in its building. Luckily, they came to an amicable agreement about operations. The result of the relationship with the Union Pacific Railroad is evident in the paragraph above that says that only the Union Pacific Railroad is running trains in the canyon today.