Minerva Terrace is one of many terraces, but it is the most popular owing to its many colors. Hot steam containing sulfer leaks out of the ground causing a yellowish color to the stones, from which the name of Yellowstone National Park was derived. The first photo is a handpainted shot of tourists in 1886. The third photo shows the 25th US Infantry Regiment Buffalo Soldiers in 1897 stopping at Minerva Terrace during their 1900 mile bicycle journey. The Army was testing iron bikes as an alternative to horses.