In the beginning, according to Arapaho accounts, the First Pipe Keeper floated on a limitless body of water with a Flat Pipe. He fasted and prayed to thw Creator, who inspired him to send the duck to search beneath the water's surface. The duck emerged with a little bit of dirt, which the Firt Pipe Keeper put on the Pipe. Then he sent the turtle to the buttom, and it too returned with dirt. The First Pipe Keeper put this dirt on the Pipe and blew it all off toward each of the four directions. In doing so, he created the earth. Then he made the sun and moon, man and woman, and vegetable and animal life, followed by day and night and the four seasons. He then taught the first people the religious rites that they would need. The duck and turtle were placed with the Pipe into a bundle, and the Arapaho descendants of that first man and woman- have been responsible for contents of the bundle are symbols of the creation, and their custody of the bundle a sacred trust.

The Arapaho believed that supernatural power, and the life force itself, emanated from the Creator, or from the "Great Mystery Above." During mythological times, the Creator infused this power into other beings, forces of nature, animals, and some minerals. The Arapaho could appeal to these supernatural beings for help. The Creators power on earth was first and foremost manifest in the Flat Pipe. The sacred bundle from the creation story was a medium through which prayers were conveyed to the Creator. The Arapaho's accounts of their past credit heroes with showing the people how to thrive in the world.

In the 1840's, the Arapaho were well known to pioneers crossing the Great Plains, but when and from where the Arapaho moved into the area is still uncertain. They were probably living on the northern Plains west of the Missouri River before the 18th century. No record exists that shows any exploers or traders who encountered them east of the Missouri, so their migration westward must have occured before the arrival of these European adventurers in the late 17th and early 18th centuries. The Arapaho language belongs to the Algonquian family. Because tribes speaking other languages from this group lived from the Atlantic coastline westward to the Great Lakes area, it seems likely that the Arapaho once lived northeast of the Missouri River and then moved westward onto the Plains

In the late 18th century, Arapaho bands on the central and southern Plains ranged from what is now southeastern Montana and eastern Wyoming south to the headwaters of the Platte River. Pressed by the Cheyenne and then hostile Sioux tribes, who had taken control of the Black Hills area, they began to move southwest. By the 19th century the Arapaho controlled the area known as the Parks and adjacent Plains in what is now westcentral Colorado and were warring with several neighboring tribes there, the Ute, Crow, and the Pawnee. They were also making more frequent raids on the Kiowa and Comanche to the south in order to increase their supply of horses. In the early 19th century the Arapaho frequently came in contact with American fur trappers in the foothills of the Rocky Mountains and near the headwaters of the Platte and Arkansas rivers. The traders referred to them by the Crow Indian's name for te tribe, "Alappaho" which meant "People with many tattoos." Arapaho men commonly had three small circles tattoed horizontally across their chests. Women had a single circle tattoed upon their foreheads. The tattoos were made by pricking the skin with cactus spines and rubbing powdered charcoal into the wound. This left a sky-blue mark after healing. The traders pronunciation of this name led to the widespread use of the name Arapaho.

Ritual, prayer, sacrifice, and other signs of religious devotion permeated all aspects of Arapaho life. The Arapaho's decorative art was shaped by prayers and visions, their quest for subsistence was guided by ceremonial acts. From birth to death, concern about relating to the Creator shaped every Arapaho's everyday life.