Ten cavalry units served at Fort Yellowstone: 1st, 3rd, 4th, 5th, 6th, 7th, 8th, 11th, and 13th cavalries. The men were selected for their skills in mountain living.

A large cavalry barracks, identical to the eastern barracks building, was built to hold 60 men and was located opposite of the New Guardhouse, completed in 1910. The barracks building was razed in the 1980s. The New Guardhouse still serves as the park jail.

As a consequence of their good work, the beauties of the park are no longer defaced; no fires have ravaged the forests; poaching has diminished to a small percentage of what it was ten years ago; and more than all, order exists everywhere.
-George Anderson, third military superintendent, 1897