Mammoth was known as Fort Yellowstone from 1886 to 1918, when the US Army managed the park from this collection of buildings. Elk regularly graze the manicured lawns of the campus-like historic and administrative center, bringing traffic to a standstill, and the high-pitched cries of bugling elk echo around the region in fall.
If you’re particularly interested in park history, pick up the Fort Yellowstone Historic District Tour Guide brochure just outside the visitor center for a self-guided tour of the fort’s original buildings. The tour takes in the former jail, barracks, granary and stables, most of which have been converted into employee residences. The guardhouse at the end of the row once controlled all public access to the park. If you're here on a Sunday morning, pop into the lovely English-style church (1913), where the stained-glass windows depict Old Faithful and Yellowstone Falls. (You can even get married here.) Other notables include the green-tiled Chinese-style roof of the chief engineer’s office (nicknamed the ‘pagoda’) and the bear statues that guard the entrance to the historic post office. History fans should walk north of the post office to see the dilapidated cabin used by the park's first mail carrier in 1895.
Rangers lead hour-long history walks daily at 5pm, departing from the visitor center. The picnic tables in front of the center mark the former parade ground.