The wagons frightened the herds.

The emigrants hunted indiscriminately, killing buffalo for meat and sport and hides.

The grass along the trail corridors was grazed by emigrant cattle and horses, degrading the rangelands that supported the buffalo.

And the emigrants kept coming.

Hundreds of thousands of them, in the 1850s and 1860s, moving through the plains as if the people who lived there were simply not present.

The United States government attempted to manage the growing conflict between emigrant settlers and Plains nations through a series of treaties.

The Fort Laramie Treaty of 1851 recognized the territories of the various Plains nations and guaranteed safe passage to emigrants in exchange for payments of goods and provisions.

The Northern Cheyenne, along with the Lakota, Arapaho, and other nations, signed this agreement.

It did not hold.

Within years, the agreed boundaries were being violated.