Hysham developed as a typical Montana rural community where people obtained supplies and services, socialized, and shipped products to market by rail and highway. Beginning about 1899, Charlie Hysham ran cattle south of the Yellowstone River and north of the Wyoming border, much of it on land leased from the Crow Indians. In 1901, the Northern Pacific Railway built a siding so he could ship cattle to Chicago and other markets. In 1906, President Theodore Roosevelt reduced the size of the reservation, opening the area to non-Indian settlement, and as homesteaders increased, buildings grew up around the railroad siding. The settlement gained a post office in 1907, and in 1908 homesteaders and schoolteacher Ada Channell platted part of her property as the new town of Hysham, named for the cattleman who had lived there for nearly a decade. By 1914, Hysham had a bank, church, two saloons, a restaurant, barbershop, lumber yards, a railroad depot, a crack baseball team, and other amenities important to area residents. In 1919, the state legislature created Treasure County from part of Rosebud County, hoping the new county's name would attract more settlers and businesses, and Hysham became the county seat. Located on the Yellowstone Trail, later U.S. Highway 10, Hysham and Treasure County have seen changing fortunes and population over the years but remain an important trade center in eastern Montana. In February 1876, during the Centennial Campaign, the U.S. Army began a three-pronged attack on Lakota and Northern Cheyenne people who had refused to return to their reservations after an ultimatum. Colonel John Gibbon's Montana Column marched down the Yellowstone Valley from Forts Shaw and Ellis, reached the area in late April 1876, found a deserted Fort Pease nearly untouched, occupied it while patrolling the north side of the Yellowstone River, and then moved to the Rosebud Creek confluence in mid-May. After the Little Bighorn defeat, the Montana Column and the decimated Seventh Cavalry occupied the trading post there for nearly a month while awaiting resupply and reinforcement.