The next year, both Thomas Fitzpatrick (agent of Upper Platte and Arkansas) and David D. Mitchell (superintendent at Saint Louis) recommended a council with the tribes to prevent a conflict.
[5] The United States government undertook negotiations with the Plains Tribes living between the Arkansas and Missouri rivers to ensure protected right-of-way for the migrants.
Representatives from the Lakota Sioux (Red Fish, Lone Horn),[8] Cheyenne, Assiniboine, Gros Ventre, Mandan, Arikara, Hidatsa, Shoshone, Crow (Big Robber, Sits-on-Edge-of Fortification),[9] and Arapaho took part in the treaty discussions.
[1] The Lakota Sioux received exclusive treaty rights to the Black Hills (now in South Dakota), to the consternation of the Cheyenne and the Arapaho.
"[13] The Cheyenne and Arapaho, the southernmost of the treaty tribes, held an area southward of the North Platte in common (now mainly in Wyoming and Colorado).
[16] In 1864, Colonel John M. Chivington's armies perpetrated the Sand Creek massacre against a peaceful camp of mostly Cheyennes, killing and mutilating the bodies of many men, women, and children.
[17] The situation escalated in 1854 with the Grattan affair, when a detachment of U.S. soldiers illegally entered a Sioux encampment to arrest those accused of stealing a cow, and in the process sparked a battle in which Chief Conquering Bear was killed.
The U.S. Army did not enforce treaty regulations and allowed hunters onto Native land to slaughter buffalo, providing protection and sometimes ammunition.
[26] Before long, the Crows saw their western Powder River area flooded with trespassing Lakotas in search of bison, and "... large scale battles with invading Sioux" took place near what is now the city of Wyola, Montana.
It is located entirely within the boundaries of the 1851 Crow territory, after the Indians in question had "earned the right to stay in the north" after the Fort Robinson outbreak.
[34] The treaty territory of the Assiniboine south of the Missouri was just a small portion of the wide range used by these northern plains Indians.