Although the setting for this railroad bridge appears serene, the impending arrival of a large, noisy steam engine could, at any moment, destroy its tranquility. Railroads connected people to places far and wide, but in passing through remote regions they altered once-pristine landscapes. Overcoming geological obstacles, like this narrow body of water, was a significant feat. The locomotive's path required bridges, trestles, tunnels, and other engineering constructions for the "iron horse" to run smoothly.

Alexander Gardner made this image while documenting the construction of a rail line to California for the Kansas Pacific and Union Pacific Railroads.