The Arapaho historically came from in the plains of Eastern parts of Colorado and Wyoming.
They are loosely connected to the Cheyenne and to a degree The Black foot people.
There is no direct historical evidence when or why they moved out onto the plains.
It could be before that time they grew they grew corn or maze or other varieties of plants before moving on to the plains and the region of Kansas, Colorado, and eventually
Montana and Wyoming.
They eventually split into the Northern and Southern Arapaho bands.
The northern Arapaho were known as the “Nankhaaseinan meaning.
Sagebrush people” the Southern Arapaho were known as the “noowunenno meaning Southern People”.
Conflict was common amongst different tribes out on the plains.
So eventually they formed alliances with other tribes notably with Sioux and Cheyenne. Their common adversaries were the Crow, Ute Pawnee, and Shoshone tribes plus white settlers.
Like all plains Indians the Arapaho were war like and often in conflict with other tribes.
They adopted most of the traditional ways of other plains tribes.
There were five divisions within the Arapaho nation each with their own dialects.
Their way of life was very similar to all other plains Indians hunting Buffalo, Elk, mountain goats and collecting fruits and various s wild vegetables to very their diets.
Like all Indian people they were caught up in the battle for land with the settlers and had many conflicts with them and the U.S Army.
They also took part in The Battle of the Little Big horn .and had their own massacre that took place in what is known as the Sand creek massacre in November of 1864.this included the Cheyenne.
Eventually the Arapaho were moved of their land and put on to reservations along with other tribes.
Today there are two halves of Arapaho tribe.
One half live on a reservation which belongs to them and is governed by them. They do however share this land with the Shoshone.
These are The Northern Arapaho and today they live on the Wind river Range and owl creek mountains with the Shoshone.
The other half known as the Southern Arapaho live on trust land with the Cheyenne in what is to day Oklahoma .