These form objects of traffic, or objects of depredation, and in this way pass from tribe to tribe over great tracts of country.

The horses owned by the Arickaras are, for the most part, of the wild stock of the prairies; some, however, had been obtained from the Poncas, Pawnees, and other tribes to the southwest, who had stolen them from the Spaniards in the course of horse-stealing expeditions into Mexican territories.

These were to be known by being branded; a Spanish mode of marking horses not practiced by the Indians.
As the Arickaras were meditating another expedition against their enemies the Sioux, the articles of traffic most in demand were guns, tomahawks, scalping-knives, powder, ball, and other munitions of war.
The price of a horse, as regulated by the chiefs, was commonly ten dollars' worth of goods at first cost.

To supply the demand thus suddenly created, parties of young men and braves had sallied forth on expeditions to steal horses; a species of service among the Indians which takes precedence of hunting, and is considered a department of honorable warfare.
While the leaders of the expedition were actively engaged in preparing for the approaching journey, those who had accompanied it for curiosity or amusement, found ample matter for observation in the village and its inhabitants.

Wherever they went they were kindly entertained.