Building the railroad required a constant supply of timber to build railroad ties. The ties were cut from timber in the mountains surrounding Laramie, including the logs in this photograph, which were cut down in the Medicine Bow Mountains southwest of Laramie.
The ties were milled in the mountains, floated down the rivers to a Union Pacific Railroad location and finally transported to the end of the line to be used in the track.
Learn more about the building of the Transcontinental Railroad.