The U.S. government in 1876 ordered the Sioux and the Cheyenne back onto the reservation. The Indians refused, and the Army was dispatched to compel them back. Three columns of infantry set out. The first column to arrive in Indian country divided, sending Gen. George Custer and the Seventh Cavalry on ahead to seek the hostiles. They found the combined Cheyenne and Sioux force (perhaps 3,000 warriors) on June 26, 1876. Custer rashly decided to do battle alone, and his entire command (265 men) was destroyed.

The next year, the Nez Percé under Chief Joseph fled from their Oregon homeland across Idaho and Montana, attempting to reach sanctuary in Canada. After a battle with the U.S. Army at the Big Hole in western Montana, the Nez Percé fled south to the Yellowstone Park area and then veered north, hoping to escape into Canada near Havre. Thirty miles from the border, Gen. Nelson Miles overtook the fleeing tribe. The Nez Percé, of Northwest origins, were sent to reservations in Oklahoma.

Custer’s annihilation notwithstanding, by 1877 all of the Indians in Montana were incarcerated on reservations. In fact, many forces besides the Army had worked to weaken and inevitably subjugate the Indians. Diseases introduced from white settlements devastated Indian populations. An outbreak of smallpox among the Blackfeet in 1837 is reckoned to have killed three quarters of the tribe. Alcohol, illegally traded to the Indians, corrupted and debilitated the traditional warrior societies.

As trade evolved from peltry to buffalo robes, the Indians were unwittingly involved in exterminating the animal that provided the cornerstone of their entire traditional culture. Before white settlers reached the plains, 60 million buffalo lived in North America. By 1870, that number was down to 10–20 million. By 1883, after railroads crossed the West and settlers were streaming in after the Civil War, there were only 100–200 buffalo left in the United States.

With the buffalo largely exterminated, Native Americans were reduced to complete dependence on handouts from the government’s Indian agents. By the mid-1880s the federal government spent $7 per year per Indian on a reservation, while it spent $1,000 per year on a soldier stationed in Montana’s Indian land.