A solider lived with the rest of his company in the Troop Barracks (structure in front of you).
A typical day began at 5:30 am, at the stable, just behind the barracks where the horses were fed. From that time until almost noon, soldiers groomed their mounts, inspected their equipment, and fed and watered the horses at least one more time.
The rest of the day might be spent patrolling the Mammoth Hot Spring Terraces to prevent visitors from chipping away souvenirs, practicing on the firing range, or participating in ceremonies and demonstrations for visiting dignitaries.
At the Post Exchange (structure to the left of you) a soldier with free time could spend it in the gymnasium or bowling alley, or could play cards, drink beer, and buy sundries.
If this entertainment became too stale, he might walk five miles to the town of Gardiner, Montana. There he could drink, gamble, and visit the "houses of ill repute." Of course, after the fun, the five mile hike uphill to the post was a stern reminder of the "wages of sin."
Upper left photo caption - Interior view of cavalry barracks, circa 1910.
Lower right photo caption - Interior view of the Fort Yellowstone Post Exchange, circa 1900 (this structure was replaced by the present building in 1905).