Little Missouri was founded in 1880 at the site of the Northern Pacific Railroad section house and depot on the west bank of the river. In late 1880, Frank Moore, the post trader of the nearby military cantonment, opened the Pyramid Park Hotel. As the badlands became a destination for hunters, scientists, and tourists, the town’s business community grew to include Big-Mouthed Bob’s Bug Juice Dispensary, a general store, and a boarding house. In 1883, President Chester A. Arthur, returning from Yellowstone National Park on September 2, and the future president Theodore Roosevelt, who came west to hunt on September 8, arrived by train at Little Missouri. The Marquis de Mores arrived in April 1883 and established Medora on the east side of the river. As Medora grew, Little Missouri declined. Plans to move the Little Missouri depot to another station failed because the structure was too wide to fit through the railroad bridges, so it was sold locally and taken to the HT Ranch about 40 miles south of Medora.
